Microscopic studies of human press fit titanium hip prostheses

Seven cementless, press fit, rectangular cross section, titanium alloy femoral prostheses were implanted for the treatment of displaced subcapital hip fractures in elderly patients and retrieved postmortem for microscopic evaluation. The mean patient age was 88 years (range, 66-103 years), and prostheses were in situ an average of 29 months (range, 6-45 months). Microscopic examination of the specimens revealed regions of bone to prosthesis contact without interposed connective tissue, and all were considered stably osseointegrated. The mean microscopic bone to prosthesis contact for five cross sections was 28%. Implantation of this prosthesis achieved satisfactory primary stability in endosteal cortical bone in these elderly patients. Secondary stabilization was apparent, as evidenced by new, viable bone formation and remodeling in apposition to the prosthesis.     

Evidence that Fe-NTA-induced renal prostaglandin F2 alpha is responsible for hyperplastic response in kidney: implications for the role of cyclooxygenase-dependent arachidonic acid metabolism in renal tumor promotion

Oxidative stress in a tissue activates phospholipase A2 which releases free arachidonic acid. In addition, a low grade oxidative tone also stimulates the tissue cyclooxygenase activity. Cyclooxygenase-dependent arachidonic acid metabolites such as PGF 2 alpha are known to play an important role in the development and maintenance of hyperplasia in skin in response to the application of tumor promoters. In this study we show that Fe-NTA, an oxidant renal tumor promoter induces PGF 2 alpha which was maximum at 12 hours after Fe-NTA treatment. However, at all time points studied, the elevated levels of PGF 2 alpha have been observed. As a result of the induction of PGF 2 alpha, the hyperplastic response can also be observed in the histopathology of the tissue. Additionally, an increased incorporation of [3H]thymidine in renal DNA has also been observed. Pretreatment of animals with indomethacin suppresses Fe-NTA-mediated hyperproliferation suggesting a role of cyclooxygenase in Fe-NTA-mediated stimulation of hyperplastic activity. The pretreatment of animals with the chain breaking antioxidants, Vit. E, BHA and BHT were only partially effective in inhibiting Fe-NTA-mediated PGF2 alpha production, further suggesting a role of non-free radical-dependent mechanism in its production. Our data suggest that Fe-NTA-induced PGF2 alpha through the activation of cyclooxygenase is responsible for the development and maintenance of hyperplasia in kidney.     

Pediatric hemifacial spasm: the efficacy of microvascular decompression

Hemifacial spasm (HFS), generally a disease of the elderly, is caused by vascular compression of the seventh nerve. Vascular compression is thought to result from atherosclerotic changes within the vessels of the posterior fossa, and therefore rarely presents in childhood. Here we describe our experience with 12 patients with onset of HFS during childhood (age 18 or less) and who had surgical exploration of the cerebellopontine angle. These patients represent less than 1.2% of the patient population with HFS operated upon at this institution during the study period. Nine patients had follow-up data extending over 83 months. All 12 patients were found to have microvascular compression of the seventh nerve at the time of surgery. The most common operative finding was compression of the seventh nerve by a vein, alone or in combination with a branch of the anterior inferior cerebellar artery. At the time of discharge and after a mean follow-up period of 125 months, microvascular decompression resulted in complete relief of spasm in 67% of the patients.     

The incidence of low-pressure urethra as a function of prolapse-reducing technique in patients with massive pelvic organ prolapse (maximum descent at all vaginal sites)

OBJECTIVE: Our aims were to compare several prolapse-reducing techniques during urodynamic evaluation and prospectively evaluate their usefulness in identifying the incidence of low urethral closure pressure in continent patients with massive prolapse. STUDY DESIGN: This preoperative, prospective, repeated-measures urodynamic study evaluated the maximum urethral closure pressure with the use of four different techniques in 30 consecutive continent patients with grade 4 prolapse at all vaginal sites. Twenty patients with grade 0 prolapse served as the control group. All patients from the prolapse group underwent surgical treatment and were followed up clinically for a minimum of 1 year. RESULTS: Use of the Scopette (Birchwood Laboratories, Eden Prairie, Minn.) reduction technique to reduce the prolapse in a linear orientation during multichannel urodynamics revealed a 56% incidence of low-pressure urethra and an overall genuine stress urinary incontinence of 83% in patients with massive pelvic organ prolapse but without clinical urinary incontinence. CONCLUSIONS: There may be an increased indication for sling urethropexy in patients with massive prolapse.     

Effect of concentration, pH, and preservative on in vitro transcorneal permeation of ibuprofen and flurbiprofen from non-buffered aqueous drops

Influence of drug concentration, pH of aqueous drops and some commonly used preservatives on in vitro transcorneal permeation of ibuprofen and flurbiprofen were investigated using goat cornea. Increase in drug concentration in the drops made in normal saline resulted in increase in quantity permeated but decrease in cumulative percent permeation of both drugs. Permeation of each drug from 0.5% drops was maximum at acidic pH (6.4) and decreased with increase in pH of the drops. Normal saline, as a vehicle, favoured permeation of each drug, hence retained in the formulation. Benzalkonium chloride and chlorobutanol enhanced cumulative percent permeation of ibuprofen while benzalkonium chloride and phenyl mercuric nitrate increased permeation of flurbiprofen. Benzalkonium chloride being incompatible with 0.5% drops (pH 6.4) of either drug, chlorobutanol appears suitable for ibuprofen drops and phenyl mercuric nitrate for flurbiprofen drops.     

Cat carotid body chemosensory discharge (in vitro) is insensitive to charybdotoxin

Charybdotoxin (ChTX), a venom protein, suppresses Ca2+-activated K+ (K+(Ca)) currents in the glomus cell of neonatal rat carotid body. If it works similarly for cat carotid body chemoreceptors, charybdotoxin is expected to stimulate the chemosensory discharge during normoxia, and particularly hypoxia and hypercapnia. We studied the effects of charybdotoxin (20-40 nM) in vitro (perfused/superfused) on the cat carotid chemosensory discharge, and simultaneously tissue PO2 (PtiO2), as a measure of positive control. ChTX (20 nM) only increased PtiO2 and decreased carotid chemosensory discharge during hypoxia, indicating vasodilation. We conclude that K+(Ca) channels do not appear to play a significant role in chemotransduction in the cat carotid body.     

Reduction in the cumulative incidence rate of cervical cancer by one life time selective screening

PATIENT: A 35-year-old man had suffered from leukemia since September 1990. A transplantation of bone marrow was carried out in February 1994. He developed a graft-versus-host disease in November 1995. In December 1995 a keratoplasty was necessary because of a perforated corneal ulcer. 17 days later the patient noted a complete loss of vision, first in the left and one day later in the right eye. The optic nerve head was white and the retina looked ischaemic like in central retinal artery occlusion. A hypodensic area was found in the frontal brain reaching up to the optic chiasm in computer tomography. Inspite of intensive treatment the immunosuppressed patient died 4 days after he had become blind. Autopsy showed a mycotic infiltration by mucormycosis of the brain and the right optic nerve sheath. This human- pathogenic fungal infection belongs to the group of mould as well as aspergillus. CONCLUSION: Mycosis should be considered in the differential diagnosis of acute visual loss in immunosuppressed patients.     

Stroke therapy in children

OBJECTIVE: To evaluate the treatment modalities used in children (ages 1-18 years) with cerebral infarction. BACKGROUND: [corrected] Cerebrovascular disease in children is more common than once suspected but its treatment has not been rigorously studied. MATERIAL AND METHODS: We reviewed all cases of cerebral infarction at the James Whitcomb Riley Hospital for Children at the Indiana University Medical Center from 01.01.80 to 31.12.95. RESULTS: Ninety-three children who experienced ischemic strokes were followed over the past fifteen years. Fifty-seven males and thirty-six females comprised the sample. Mean age was 6.9 years at the time of stroke. No medication or surgical intervention was the therapeutic recommendation in 44% of patients. For cardioembolic strokes, warfarin was used later in the course for a few patients who went on to have atrial fibrillation or valve replacement. Aspirin was used in all patients with carotid artery dissections. Aspirin was used in most children with Moya-Moya, with calcium channel blockers and surgical intervention used in later cases. Exchange transfusion followed by monthly transfusion and chelation therapy has been the treatment of choice for children with cerebral infarction complicating sickle cell disease. CONCLUSIONS: In most instances, treatment was widely disparate, probably reflecting the lack of firm therapeutic guidelines for this age group, with a better understanding of the etiology and pathophysiology of strokes in children, multicenter, international, randomized therapeutic trials based strictly on an etiological basis should be organized in the future.     

Cryptococcosis in tree shrews (Tupaia tana and Tupaia minor) and elephant shrews (Macroscelides proboscides)

OBJECTIVE: To determine the relation between metabolic and anthropometric parameters and circulating leptin concentrations in women with polycystic ovary syndrome (PCOS). DESIGN AND PATIENTS: Correlation of fasting serum leptin concentrations with anthropometric measures and multiple metabolic parameters including insulin and glucose responses to a 2-hour 75-g oral glucose tolerance test (OGTT) in 85 women with PCOS (17-36 years, body mass index (BMI) 29.9 +/- 0.9 kg/m2, mean +/- SD) and 18 control women (25-47 years, BMI 25 +/- 1.7 kg/m2). Diagnostic criteria for PCOS: characteristic ovarian morphology on ultrasound plus at least two of (1) elevated serum testosterone; (2) elevated serum androstenedione; and (3) reduced serum SHBG concentrations. MEASUREMENTS: Concentrations of androgens, lipids, PRL, gonadotrophins, and leptin were measured in the baseline fasting blood sample from an OGTT. Insulin and glucose were measured throughout OGTT. Serum leptin concentrations were measured by radioimmunoassay. RESULTS: Log leptin levels in the PCOS group correlated significantly with BMI (r = 0.85, P < 0.0001) and with 8 other parameters including waist/hip ratio (r = 0.51, P = 0.0005). By stepwise regression analysis, only BMI (P < 0.0001) and plasma high density lipoprotein concentration (P = 0.02) were independently correlated with log leptin levels, both positively. There was no effect of fat distribution, as measured by waist/ hip ratio, on leptin concentrations. Comparison of control subjects to a BMI-matched subgroup of 55 PCOS subjects revealed significantly higher circulating concentrations of LH, testosterone, DHEAS, progesterone and androstenedione, and higher glucose and insulin responses to OGTT in the PCOS group. Leptin levels were not different between the PCOS subgroup and control group (14.8 +/- 1.3 vs 12.1 +/- 2.3 micrograms/l, mean +/- SE, P = 0.26) and the relation of BMI to leptin levels determined by linear regression analysis also did not differ between the two groups. CONCLUSIONS: Our results indicate that circulating leptin concentrations in women with PCOS, a condition characterized by hyperandrogenaemia, increased LH concentrations and insulin resistance, are strongly related to BMI and not independently affected by circulating levels of insulin, gonadotrophins or sex hormones.