The human myotendinous junction: an ultrastructural and 3D analysis study.

The myotendinous junction (MTJ) is a specialized structure in the musculotendinous system, where force is transmitted from muscle to tendon. Animal models have shown that the MTJ takes form of tendon finger-like processes merging with muscle tissue. The human MTJ is largely unknown and has never been described in three dimensions (3D). The aim of this study was to describe the ultrastructure of the human MTJ and render 3D reconstructions. Fourteen subjects (age 25 ± 3 years) with isolated injury of the anterior cruciate ligament (ACL), scheduled for reconstruction with a semitendinosus/gracilis graft were included. Semitendinosus and gracilis tendons were stripped as grafts for the ACL reconstruction. The MTJ was isolated from the grafts and prepared for transmission electron microscopy (TEM) and focused ion beam/scanning electron microscopy. It was possible to isolate recognizable MTJ tissue from all 14 patients. TEM images displayed similarities to observations in animals: Sarcolemmal evaginations observed as finger-like processes from the tendon and endomysium surrounding the muscle fibers, with myofilaments extending from the final Z-line of the muscle fiber merging with the tendon tissue. The 3D reconstruction revealed that tendon made ridge-like protrusions, which interdigitiated with groove-like indentations in the muscle cell.

Non-hematopoietic PAR-2 is essential for matriptase-driven pre-malignant progression and potentiation of ras-mediated squamous cell carcinogenesis.

The membrane-anchored serine protease, matriptase, is consistently dysregulated in a range of human carcinomas, and high matriptase activity correlates with poor prognosis. Furthermore, matriptase is unique among tumor-associated proteases in that epithelial stem cell expression of the protease suffices to induce malignant transformation. Here, we use genetic epistasis analysis to identify proteinase-activated receptor (PAR)-2-dependent inflammatory signaling as an essential component of matriptase-mediated oncogenesis. In cell-based assays, matriptase was a potent activator of PAR-2, and PAR-2 activation by matriptase caused robust induction of nuclear factor (NF)κB through Gαi. Importantly, genetic elimination of PAR-2 from mice completely prevented matriptase-induced pre-malignant progression, including inflammatory cytokine production, inflammatory cell recruitment, epidermal hyperplasia and dermal fibrosis. Selective ablation of PAR-2 from bone marrow-derived cells did not prevent matriptase-driven pre-malignant progression, indicating that matriptase activates keratinocyte stem cell PAR-2 to elicit its pro-inflammatory and pro-tumorigenic effects. When combined with previous studies, our data suggest that dual induction of PAR-2-NFκB inflammatory signaling and PI3K-Akt-mTor survival/proliferative signaling underlies the transforming potential of matriptase and may contribute to pro-tumorigenic signaling in human epithelial carcinogenesis.

Bacteraemia as a result of Campylobacter species: a population-based study of epidemiology and clinical risk factors.

Invasive disease as a result of Campylobacter is rarely reported. We reviewed 46 cases of blood stream infection with Campylobacter in a Danish population with complete follow-up. The incidence was 2.9 per 1 million person-years with a peak incidence in the age group above 80 years. In the population, the ratio of notified bacteraemia/enteritis patients with Campylobacter infection was 0.004. Patients with bacteraemia were older and had higher comorbidity, e.g. alcoholism, immunosuppression, previous gastrointestinal surgery or HIV infection. We found 26% of blood isolates resistant to ciprofloxacin. The length of hospitalization was significantly longer in bacteraemia patients, whereas the outcome was favourable with 28-day mortality of 4% in bacteraemia patients and 1% in enteritis patients. None of the bacteraemia patients relapsed within 365-day follow-up.

Exogenous estrogen boosts circulating estradiol concentrations and calcium uptake by duodenal tissue in heat-stressed hens.

In the hen, heat stress (HS) disrupts shell calcification and reproductive processes, including hormone synthesis and egg production. Two studies were conducted to investigate palliative effects of exogenous estrogen or dietary vitamin D3 on Ca homeostasis and reproductive physiology during HS. Study 1: Hy-Line W36 hens were randomly assigned to thermoneutral (TN) or HS treatments and to 1 of 7 estrogen treatments: zero (control) or one Compudose 200 implant given 1, 2, 3, 8, 9, or 10 d before onset of HS. With no implant, HS reduced plasma estradiol (E2) and total Ca absorbed (CaT) by duodenal cells (P < 0.05). In TN hens with implants, plasma E2 tripled within 24 h (P < 0.05) and remained elevated (P < 0.05) through d 9. In HS hens with implants, plasma E2 rose 6-fold (P < 0.05) to equal TN+E2 concentrations and remained elevated through d 10. In TN and HS hens with implants, the rate of Ca absorption (CaTR) and CaT increased dramatically; the responses were quadratic and essentially identical. Study 2: Hy-Line W36 hens were provided diets formulated either according to NRC requirements (NRC, 1994), or with the addition of 22,000 IU/kg vitamin D3 (+VD hens). A 24-h HS episode was imposed 2 wk after initiation of the dietary regimen. Duodenal samples were collected for Ca absorption assays after the 24-h HS episode. Both CaTR and CaT in +VD hens were approximately 3-fold higher than in hens in the NVD group (P = 0.102). The results lead to the conclusion that exogenous estrogen, high levels of dietary vitamin D, or both, before a HS episode, are efficacious in alleviating at least some of the effects of HS and should be further investigated.

Role of estrogen in avian osteoporosis.

One of the difficulties associated with commercial layer production is the development of osteoporosis in hens late in the production cycle. In light of this fact and because of hens' unique requirements for Ca, many studies have focused on the regulation of Ca and the role of estrogen in this process. The time course of estrogen synthesis over the productive life of hens has been well documented; increased circulating estrogen accompanies the onset of sexual maturity while decreases signal a decline in egg production prior to a molt. Numbers of estrogen receptors decrease with age in numerous tissues. The parallel changes in calcium-regulating proteins, primarily Calbindin D28K, and in the ability of duodenal cells to transport Ca, are thought to occur as a result of the changes in estrogen, and are also reversible by the molt process. In addition to the traditional model of estrogen action, evidence now exists for a possible nongenomic action of estrogen via membrane-bound receptors, demonstrated by extremely rapid surges of ionized Ca in chicken granulosa cells in response to 17beta-estradiol. Estrogen receptors have also been discovered in duodenal tissue, and tamoxifen, which binds to the estrogen receptor, has been shown to cause a rapid increase in Ca transport in the duodenum. In addition, recent evidence also suggests that mineralization of bone per se may not explain entirely the etiology of osteoporosis in the hen but that changes in the collagen matrix may contribute through decreases in bone elasticity. Taken together, these studies suggest that changes in estrogen synthesis and estrogen receptor populations may underlie the age-related changes in avian bone. As with postmenopausal women, dietary Ca and vitamin D are of limited benefit as remedies for osteoporosis in the hen.

Western immunoblotting in avian shell gland sample immunoblotting methods.

Avian shell gland tissue was subjected to Western blot analysis using anti-human estrogen receptor-alpha antibody H222. Initial attempts to obtain consistent, high-quality blots were unsuccessful because, as it turned out, excessive lipid in tissue preparations interfered with protein separation. Incremental additions of acetone eventually proved to be the critical step in solubilizing lipids and allowing consistent separation of bands on gels. A detailed description of the methodology is presented.

Estrogen receptor-alpha populations change with age in commercial laying hens.

Older hens in production lay larger but fewer eggs than younger birds, and the incidence of soft and broken shells is greater in older hens than younger. These changes are attributable at least in part to changing hormone profiles and diminished ability of the hen to transport calcium at the duodenum. In further exploration of this relationship, a study was conducted with three ages of Hy-Line W-36 birds: prelay pullets (PL; 19 wk, 0% production), peak-production hens (PP; 29 wk, approximately 93% production), and late-stage hens (LS; 71 wk, approximately 80% production). Hens from the PP and LS groups were palpated for presence of an egg in the shell gland; hens were then euthanized and tissues (kidney, shell gland, hypothalamus) were removed for quantification of estrogen receptor-alpha (ERalpha) populations via immunocytochemical and Western blot analyses. Localization of ERalpha by immunostaining in the shell gland showed differences among age groups; however, no differences were noted in localization of ERalpha between age groups in the kidney and hypothalamus. In both the kidney and the shell gland there was a decrease in the amount of ERalpha, as detected by immunoblotting, in the LS hens compared to PL and PP birds (P < 0.05). The results suggest that failure of calcium regulating mechanisms with age may be mediated at least in part through the reduced populations of estrogen receptors in certain critical tissues.

Small cerebral aneurysms presenting with symptoms other than rupture.

BACKGROUND: Recent natural history studies have suggested that unruptured intracranial aneurysms smaller than 1 cm have a low risk of rupture. Symptomatic aneurysms may be underrepresented in natural history studies because they are preferentially treated. The authors compared the number of patients with symptoms caused by unruptured intracranial aneurysms smaller than 1 cm treated surgically at their institution with similar patients enrolled in the International Study of Unruptured Intracranial Aneurysms (ISUIA) from their institution over the same time period. METHODS: The records of all unruptured aneurysms treated surgically at the Mayo Clinic from 1980 through 1991 were reviewed. There were 97 patients with 117 unruptured aneurysms smaller than 1 cm by angiography. Aneurysms with a history of rupture or larger than 1 cm on cross-sectional imaging were excluded from analysis. The presence and characteristics of symptoms directly attributable to the aneurysm were recorded. Comparison was made with patients from the Mayo Clinic enrolled in the ISUIA retrospective natural history cohort over the same time period. RESULTS: Of the 97 patients studied, 15 presented with symptoms other than rupture (15.5%). The symptoms were third nerve deficit (seven patients), cerebral ischemia owing to emboli originating from within the aneurysm (five patients), and visual acuity loss (three patients). Eleven other aneurysms had possibly but not definitively caused symptoms; these were considered asymptomatic. No patient from the Mayo Clinic enrolled in the retrospective cohort of the ISUIA had a symptomatic aneurysm smaller than 1 cm on both angiography and cross-sectional imaging. CONCLUSIONS: Unruptured intracranial aneurysms smaller than 1 cm occasionally present with neurologic symptoms. These symptoms are typically owing to mass effect on the second and third cranial nerves or cerebral ischemia as a result of emboli originating from within the aneurysm. Patients with symptomatic unruptured aneurysms less than 1 cm at the Mayo Clinic were preferentially treated. Although existing natural history data may be applied to most unruptured aneurysms, small symptomatic aneurysms may be underrepresented in natural history studies.

Ischemic complications of surgery for anterior choroidal artery aneurysms.

OBJECT: Anterior choroidal artery (AChA) aneurysms account for 4% of all intracranial aneurysms. The surgical approach is similar to that for other supraclinoid carotid artery lesions, but surgery may involve a higher risk of debilitating ischemic complications because of the critical territory supplied by the AChA. METHODS: Between 1968 and 1999, 51 AChA aneurysms in 50 patients were treated using craniotomy and clipping at the Mayo Clinic. There were 22 men (44%) and 28 women (56%) whose average age was 53 years (range 27-79 years). Twenty-four AChA aneurysms (47%) had hemorrhaged; nine patients (18%) had subarachnoid hemorrhage from another aneurysm. Three AChA aneurysms (6%) were associated with symptoms other than rupture. Forty-one patients (82%) achieved a Glasgow Outcome Scale (GOS) score of 4 or 5 at long-term follow up. The surgical mortality rate was 4%, and major surgical morbidity (GOS < or = 3) was 10%. Eight patients (16%) had clinically and computerized tomography-demonstrated AChA territory infarcts. Five of these strokes manifested in a delayed fashion 6 to 36 hours after the operation, and progressed from mild to complete deficit over hours. In 41 patients the aneurysm arose from the internal carotid artery adjacent to the AChA, and in nine patients the aneurysm arose directly from the origin of the AChA itself; four of these nine patients had postoperative infarction. CONCLUSIONS: Surgical treatment of AChA aneurysms involves a significant risk of debilitating ischemic complications. Most postoperative strokes occur in a delayed fashion, offering a potential therapeutic window. Patients with aneurysms arising from the AChA itself have an extremely high risk for postoperative stroke.

Folk remedies and child abuse: a review with emphasis on caida de mollera and its relationship to shaken baby syndrome.

OBJECTIVE: There were two objectives: first, to make the reader familiar with folk remedies that might be confused with child abuse; second, to challenge the idea existing in the literature that treatment for the Hispanic folk illness caida de mollera can cause the injuries seen in the shaken baby syndrome. METHOD: Literature review and analysis with case application were used. RESULTS: A wide variety of folk remedies with potential for confusion with child abuse were found to exist, and were described. Treatment for caida de mollera was found to consist of a number of gentle, nonviolent maneuvers quite different from the violent shaking believed to cause shaken baby syndrome. CONCLUSIONS: Familiarity with folk remedies will help differentiate them from child abuse. The child protection community would benefit from realizing that treatment for caida de mollera is an improbable cause of shaken baby syndrome injuries.

Rapid detection of cytomegalovirus in bronchoalveolar lavage fluid and serum samples by polymerase chain reaction: correlation of virus isolation and clinical outcome for patients with human immunodeficiency virus infection.

Bronchoalveolar lavage (BAL) fluids and serum samples from 153 patients with pulmonary symptoms who were infected with human immunodeficiency virus (HIV) and underwent BAL were examined for the presence of cytomegalovirus (CMV) by conventional culture and by polymerase chain reaction (PCR) for detection of CMV DNA. PCR detected CMV more frequently than did cultures of BAL fluid (PCR of BAL fluid, 53%; PCR of serum, 40%; and culture, 30%). In a multivariate model, development of extrapulmonary CMV disease was predicted by the finding of CMV in BAL fluid by culture (relative risk [RR], 8.0; confidence interval [CI], 3.8-16.8) or the finding of CMV DNA in serum (RR, 7.4; CI, 3.2-17.3) or BAL fluid (RR, 8.0; CI, 3.1-20.7) by PCR. Mortality was found to be similar for patients who did or did not have CMV detected by either culture or PCR. Detection of CMV DNA by PCR was a more rapid and sensitive technique than conventional culture. Detection of CMV DNA in BAL fluid or serum predicted subsequent development of extrapulmonary CMV disease but not death for HIV-infected patients with pulmonary symptoms.

Marginal costs in general acute care hospitals: a comparison among California, New York and Canada.

In the present paper we offer a detailed comparison of hospital costs between California and New York and two Canadian provinces (Ontario and British Columbia) in 1981 and 1985. We find that production technologies differ significantly between the two countries and between California and New York. Marginal costs and their distributions also differ across jurisdictions and across different size hospitals. Marginal cost levels were the lowest in Canadian hospitals for almost all outputs in both years and their distribution was also the tightest. Some very mild scale effects were also present in the acute care production. Hospitals in California experienced for the most part increasing marginal costs for acute care, whereas Canadian hospitals showed the reverse pattern. In New York we find a weak negative scale effect in acute care production. Density estimates conditional on hospital output reinforce these results.

Patient-administered sequential spirometry in healthy volunteers and patients with alpha 1-antitrypsin deficiency.

The launching of cheap, pocket-sized spirometers, with data storage capability, has made patient-administered sequential spirometry (PASS) an attractive method of monitoring ventilatory capacity. At present, little information is available on the quality of PASS, compared to laboratory spirometry. The aim of this study was to investigate whether patients could perform PASS without loss of reliability and reproducibility as compared with traditional laboratory spirometry. Ten healthy volunteers performed spirometry for 1 month and 10 emphysematous patients with alpha 1-antitrypsin deficiency (type PiZ) performed spirometry twice daily for up to 2 yr. To fulfil Good Clinical Practice criteria on full data documentation, a traditional direct recording spirometer, the Vitalograph R-model, was used. A decompression device was used for calibration and a 3.8% annual drift in volume registration was noted. This drift was largest for the first year. After training, all patients were able to perform unsupervised spirometry, producing technically correct forced expiratory curves. Reproducibility of FEV1 and FVC obtained by PASS was found to be as good as for laboratory spirometry. After adjustment for the diurnal variation, the residual variation of FEV1 was 2.5% (range 1.6-4.2%) for healthy volunteers and 5.6% (range 4.2-7.7%) for emphysematous patients. Forced vital capacity showed the same pattern. In conclusion, PASS is possible in highly motivated individuals without loss of reliability and reproducibility when compared to laboratory spirometry.

Late patency of long saphenous vein bypass grafts to the anterior and posterior cerebral circulation.

To evaluate the late results and the natural history of long saphenous vein bypass grafts (SVGs) between the extracranial and intracranial circulation, the authors retrospectively analyzed 202 consecutive SVGs performed at the Mayo Clinic from 1979 to 1992. The distal anastomosis was to the vertebrobasilar system in 98 patients and to the carotid artery system in 103 patients. Surgical indications were advanced cerebroocclusive disease in 63% (127 cases), giant aneurysm in 37% (74 cases), and neoplasm in one patient. In 125 patent SVGs follow-up information was obtained for longer than 1 year and in 23 patent SVGs it was over 10 years (maximum 13 years, median 6.5 years). Most of the graft failures (76%) occurred during the 1st year after surgery, with 42% of all graft failures found during the first 24 hours after operation. Late graft attrition occurred in only 10 patients (8%). Cumulative patency at 1 year was 86% +/- 3%, at 5 years 82% +/- 4%, and at 13 years 73% +/- 19%. Neurological worsening at the time of occlusion developed in 72% of patients with early occlusion, whereas 80% of patients with late graft occlusion had no new neurological symptoms. Long-term patency of SVGs for cerebral revascularization appears to be excellent, with an average failure rate of 1% to 1.5% per year following the 1st year after surgery. To minimize early graft thrombosis, meticulous attention must be paid to technical detail.

Prostate-specific antigen obtained under optimal conditions determines extracapsular adenocarcinoma of the prostate.

OBJECTIVE: To assess the relationship of prostate-specific antigen (PSA) obtained under optimal conditions with the presence or absence of organ-confined prostate cancer following radical prostatectomy. PATIENTS AND METHODS: The medical records of 300 consecutive patients who underwent radical retropubic prostatectomy were retrospectively reviewed. Ninety-three patients were excluded who had a pre-operative PSA level potentially altered by various factors (prostate infection, manipulation or instrumentation). RESULTS: A pre-operative PSA value < 4 ng/mL accurately predicted pathologically confined disease in 42 of 51 patients (82%) which contrasted with extracapsular disease in 74 of 84 patients (88%) who had a PSA value > 10 ng/mL. One of the 53 patients with a PSA > 15 ng/mL had organ-confined disease at surgery. CONCLUSION: These data demonstrate that optimal serum PSA values correlate well with pathological stage.

Detection of cytomegalovirus DNA in serum correlates with clinical cytomegalovirus retinitis in AIDS.

The high sensitivity of nested polymerase chain reaction (PCR) offers the possibility of rapid detection of cytomegalovirus (CMV) DNA in serum. Five consecutive serum samples were examined from 52 human immunodeficiency virus (HIV)-seropositive patients (19 of whom had clinically presumed diagnosis of CMV chorioretinitis). Presence of CMV DNA in serum was shown to precede development of clinical disease. Eleven patients who developed chorioretinitis were positive for CMV DNA in serum samples obtained 3 months before clinical disease, and 3 retinitis patients who initially were negative for CMV DNA became positive with the onset of clinical retinitis. In contrast, 29 of 33 HIV-seropositive subjects without clinical CMV chorioretinitis and matched with respect to age and CD4 T cell numbers were negative for CMV DNA in all 5 serum samples. Thus, the presence of CMV DNA in serum analyzed by PCR is a good predictive marker of CMV retinitis in HIV-seropositive subjects. A positive PCR results supports the clinical diagnosis and may be useful for monitoring response to antiviral treatment.

Pyoderma gangrenosum in infants and children.

Pyoderma gangrenosum is an uncommon ulcerative skin disorder that occurs in all age groups. Approximately 4% of patients are infants and children. There are several notable differences between the childhood and adult manifestations of the disease, including the distribution of lesions and associated disorders. We reviewed the childhood cases (< or = 18 yrs of age) of unequivocal pyoderma gangrenosum in the English literature and tabulated the trends in clinical features, associated disorders, and therapy. We report our 3-week-old patient, the youngest documented case. Of the 46 patients, only 4 were less than 1 year of age. A systemic illness was present in 74% of the older children, most commonly, ulcerative colitis. Only one infant had an associated problem (HIV+) at the time of onset. Infants appear to have an unusual distribution of perianal and genital lesions not often described in other age groups. Our review suggests that pyoderma gangrenosum in children has a similar clinical appearance to that in adults. It is associated with some of the same underlying disorders, but with different frequencies. The distribution of lesions in children is similar, often involving the lower extremities, but pyoderma gangrenosum of the head and face appears to be more common in children. Infants may have ulcers in genital and perianal areas. The most frequently prescribed treatment for children is systemic corticosteroids, which generally are very effective.

High-dose epinephrine results in greater early mortality after resuscitation from prolonged cardiac arrest in pigs: a prospective, randomized study.

OBJECTIVE: To determine whether high-dose epinephrine (0.2 mg/kg) during cardiopulmonary resuscitation (CPR) results in improved outcome, compared with standard-dose epinephrine (0.02 mg/kg). DESIGN: A prospective, randomized, blinded study. SETTING: Research laboratory of a university medical center. SUBJECTS AND INTERVENTIONS: Thirty domestic swine were randomized to receive standard- or high-dose epinephrine during CPR after 15 mins of fibrillatory cardiac arrest. Three minutes of CPR were provided, followed by advanced cardiac life support per American Heart Association guidelines. Animals that were successfully resuscitated were supported for 2 hrs in an intensive care unit (ICU) setting, and then observed for 24 hrs. MEASUREMENTS AND MAIN RESULTS: Electrocardiogram, aortic blood pressure, right atrial blood pressure, and end-tidal CO2 were monitored continuously until the intensive care period ended. Survival and neurologic outcome were determined. Return of spontaneous circulation was attained in 14 of 15 animals in each group. Four of 14 high-dose epinephrine pigs died during the ICU period after return of spontaneous circulation vs. zero of the 14 standard-dose pigs (p < .05). Six standard-dose pigs survived 24 hrs vs. four high-dose pigs. Twenty-four-hour survival rate and neurologic outcome were not significantly different. Within 10 mins of defibrillation, severe hypertension (diastolic pressure > 120 mmHg) occurred in 12 of 14 high-dose pigs vs. two of 14 standard-dose pigs (p < .01). Severe tachycardia (heart rate > 250 beats/min) occurred in seven of 14 high-dose pigs vs. zero of 14 standard-dose pigs (p < .01). All four high-dose epinephrine pigs that died during the ICU period experienced both severe hypertension and tachycardia immediately postresuscitation. CONCLUSIONS: High-dose epinephrine did not improve 24-hr survival rate or neurologic outcome. Immediately after return of spontaneous circulation, most animals in the high-dose epinephrine group exhibited a hyperadrenergic state that included severe hypertension and tachycardia. High-dose epinephrine resulted in a greater early mortality rate.