Changes in skeletal collagen cross-links and matrix hydration in high- and low-turnover chronic kidney disease

Chronic kidney disease (CKD) increases fracture risk. The results of this work point to changes in bone collagen and bone hydration as playing a role in bone fragility associated with CKD.

INTRODUCTION

Clinical data have documented a clear increase in fracture risk associated with chronic kidney disease (CKD). Preclinical studies have shown reductions in bone mechanical properties although the tissue-level mechanisms for these differences remain unclear. The goal of this study was to assess collagen cross-links and matrix hydration, two variables known to affect mechanical properties, in animals with either high- or low-turnover CKD.

METHODS

At 35 weeks of age (>75% reduction in kidney function), the femoral diaphysis of male Cy/+ rats with high or low bone turnover rates, along with normal littermate (NL) controls, were assessed for collagen cross-links (pyridinoline (Pyd), deoxypyridinoline (Dpd), and pentosidine (PE)) using a high-performance liquid chromatography (HPLC) assay as well as pore and bound water per volume (pw and bw) using a (1)H nuclear magnetic resonance (NMR) technique. Material-level biomechanical properties were calculated based on previously published whole bone mechanical tests.

RESULTS

Cortical bone from animals with high-turnover disease had lower Pyd and Dpd cross-link levels (-21% each), lower bw (-10%), higher PE (+71%), and higher pw (+46%) compared to NL. Animals with low turnover had higher Dpd, PE (+71%), and bw (+7%) along with lower pw (-60%) compared to NL. Both high- and low-turnover animals had reduced material-level bone toughness compared to NL animals as determined by three-point bending.

CONCLUSIONS

These data document an increase in skeletal PE with advanced CKD that is independent of bone turnover rate and inversely related to decline in kidney function. Although hydration changes occur in both high- and low-turnover disease, the data suggest that nonenzymatic collagen cross-links may be a key factor in compromised mechanical properties of CKD.

Extraluminal endoscopic-assisted ligation of venous tributaries for infrainguinal in situ saphenous vein bypass: a preliminary report

In an attempt to obviate the need for an incision the length of the leg during in situ saphenous vein bypass, a minimally invasive operation using 'laparoscopic techniques' was developed. At operation, standard incisions were made over the proximal femoral artery/vein and the saphenous vein at the distal popliteal artery level. An angioscopic valvulotome was used to perform valvulotomy under direct vision. After valvulotomy, a distention balloon system was used to form a 'pocket' into which a laparoscope was inserted. Trocars were then inserted under direct vision and the saphenous vein dissected and side branches individually clipped. After occlusion of the venous side branches, proximal and distal arterial anastomoses were performed in the standard fashion. This minimally invasive operation using laparoscopic techniques precludes the need for a long leg incision and saphenous vein dissection, except at the proximal and distal arterial anastomoses.

Laparoscopic fundoplication in the treatment of severe gastroesophageal reflux disease: preliminary results of a prospective trial

To determine the technical feasibility and success of laparoscopic fundoplication in the treatment of severe gastroesophageal reflux disease (GERD), 18 consecutive adult patients were enrolled in a prospective study. All patients had received unsuccessful conservative treatment, were refractory to medical management, or had recurrence of symptoms of esophagitis after omeprazole therapy. All patients had severe acid reflux on 24-hour esophageal pH monitoring, endoscopic evidence of previous or ongoing esophagitis, and a defective lower esophageal sphincter on manometry. Complete (Nissen) fundoplication was done in 11 and partial (Toupet) fundoplication in 7 patients; the mean operative time was 183 minutes (range, 120 to 357 minutes). Feedings were initiated on the first postoperative day, and the average length of stay was 2.6 days (range, 1 to 6). There were no deaths or conversions to laparotomy. Postoperative morbidity consisted of transient bloating in three patients and dysphagia requiring dilatation in four patients. Return to work or normal activity averaged 19 days (range, 3 to 28), and 17 patients (94%) reported good to excellent results, with a median follow-up of 7 months. Laparoscopic fundoplication is technically feasible and offers a sound surgical alternative to patients with refractory GERD, but longitudinal follow-up is required to confirm long-term results.

Adult rhabdomyoma: presentation as a cervicomediastinal mass (case report and review of the literature)

The adult rhabdomyoma (ARM) is an unusual and extremely uncommon tumor. Only 96 cases have been reported. Adult rhabdomyomas are found most often in the region of the base of the tongue, floor of the mouth, larynx, and pharynx. Uncommon locations include the soft palate, uvula, lip and cheek, orbit, and stomach. One prior case of extension of an ARM from the supraclavicular region into the mediastinum has been described as an incidental finding at autopsy. It is important to be aware of and correctly identify this tumor because total excision may be curative. Follow-up must be long-term, as recurrence can occur after 35 years. The authors present a case of an ARM diagnosed during the evaluation and treatment of a symptomatic mediastinal mass. This ARM was found to involve the esophagus and trachea from the inferior constrictors in the neck to the azygous vein in the mediastinum. This case represents a previously undescribed presentation of an ARM. We present a review of ARM and outline our diagnostic, therapeutic, and follow-up plans.

1525 laparoscopic cholecystectomies without biliary injury: a single institution's experience

Laparoscopic Cholecystectomy (LC) has become the preferred treatment of gallbladder disease. The indications for LC remain unchanged from those for open cholecystectomy (OC). A total of 1525 patients underwent LC at Georgia Baptist Medical Center between December 1989 and December 1992. The procedure was completed in 1,492 patients (97.8%) and required conversion to OC in 33 patients (2.2%). Selective intraoperative cholangiography was used in 165 patients (10.8%). Overall morbidity was 4.06%, and there were four deaths not operatively related, for a 0.26% mortality rate. There have been no biliary ductal injuries. The average hospital stay was 0.82 days, with 37.4% of the patients going home as true outpatients and 44.5% going home on postop Day one. Most published series on LC report a small incidence of biliary injury. We feel that with meticulous dissection of the cystic duct and use of selective intraoperative cholangiography to define unsure anatomy, biliary injury can be minimized.

Yeast in the urine: solutions for a budding problem

The significance of candiduria ranges from simple procurement-related contamination to disseminated candidiasis. Ensuring that a valid urine specimen is collected and carefully assessing patients for risk factors predisposing to disseminated candidiasis permit the stratification of cases into three clinical categories: (1) asymptomatic candiduria in a previously healthy patient; (2) candiduria in a high-risk patient in whom disseminated candidiasis is unlikely; and (3) candiduria in a high-risk patient with a potential for disseminated candidiasis. Strategies for management are tailored to the individual patient. Appropriate management of anatomic genitourinary abnormalities and removal of bladder catheters may result in the resolution of candiduria, although some patients require systemic antifungal therapy. All patients with candiduria should be evaluated for evidence of deep-seated tissue infection or candidemia before therapy is instituted. Fluconazole appears to be a safe and effective agent for the management of candidal urinary tract infection. Both its safety and its ease of administration make it superior to amphotericin B for this purpose.

Genital herpes simplex infections in patients with the acquired immunodeficiency syndrome

On August 14, 1987, the Centers for Disease Control revised the surveillance case definition for the acquired immunodeficiency syndrome (AIDS) to include several indicator diseases. The addition of herpes simplex virus (HSV) infections to the definition reemphasized the increasing frequency of severe HSV infections in patients also infected with the human immunodeficiency virus (HIV). These infections in patients with AIDS are associated with considerable morbidity similar to reports of HSV in other immunocompromised populations. Their spectrum can include persistent or recurrent genital disease, severe visceral involvement, and disseminated infection. Patients with AIDS also are at increased risk of drug toxicities when receiving treatment for HSV infections in addition to antiretroviral therapy. Acyclovir, a selective and specific inhibitor of HSV replication, has been the mainstay of safe and effective treatment for HSV for more than a decade. However, reports of acyclovir-resistant strains of HSV in patients with AIDS have been steadily increasing since 1989. Although foscarnet has been successful in treating acyclovir-resistant strains, foscarnet-resistant strains have also been isolated. The search to find novel approaches for the treatment and suppression of HSV in patients with AIDS has become an added challenge in the management of this devastating disease.

Tissue penetration of clindamycin in diabetic foot infections

Serum and tissue samples were obtained during surgery from four diabetics with neuropathy who underwent debridement or amputation for foot infections while receiving clindamycin 600 or 900 mg iv. Clindamycin concentrations were assayed by radioimmunoassay. Clindamycin was detected in all serum and tissue samples (range: 0.04-2.8 mg/kg in tissues and 1.1-11.1 mg/L in serum). In nine of the eleven tissue samples the clindamycin concentration exceeded the MICs reported for many pathogens commonly involved in such infections. In only a single instance was the ratio of tissue to serum concentration < 0.13.

AIDS/HIV knowledge level and perceived chance of having HIV among rural adolescents

Behaviors that increase the risk of acquired immunodeficiency syndrome (AIDS) and human immunodeficiency virus (HIV) among adolescents living in rural areas have been reported to be as frequent as those of lower socioeconomic minority youth living in large urban areas. Little is known, however, about whether rural adolescents possess adequate knowledge upon which to make responsible decisions to avoid exposure to HIV. In order to address this deficit, we administered the Centers for Disease Control (CDC) 1989 Secondary School Health Risk Survey to 294 sixth, seventh, and eighth grade students (30.2% sample) from a rural county with significant social problems including epidemic sexually transmitted diseases STDs, sex-for-drugs, poverty, and drug abuse. The sample was 65% African-American, 50% female, with a mean age of 12.9 +/- 1.3 years. Although 68% reported having received school-based AIDS education, a lower proportion (greater than or equal to 10%) the students were found to correctly answer 8 of 17 AIDS/HIV knowledge questions than those from a national comparison group. The mean was 12.8 +/- 3.1 of 17 items answered correct. Lower AIDS/HIV knowledge was associated with lower school grade (rho = 0.46, p less than or equal to 0.0001); being African-American, Hispanic, or Native American (p less than or equal to 0.043); and never receiving school-based AIDS/HIV education (p less than or equal to 0.0001). Based on multivariate analysis of variance (ANOVA), only school-based AIDS/HIV education was a significant predictor (p less than or equal to 0.0001) of knowledge.(ABSTRACT TRUNCATED AT 250 WORDS)

Infection due to the fungus Acremonium (cephalosporium)

Human infections due to fungi belonging to the genus Acremonium occur uncommonly, but unlike infections due to other filamentous fungi, usually affect immunocompetent individuals. Mycetoma, which usually develops following trauma, is the most common infection caused by Acremonium spp. Other sites of infection include the eye (generally following abrogation of ocular defenses), colonizing disease of the lung and gastrointestinal tract, as well as locally invasive infections such as osteomyelitis, sinusitis, arthritis, and peritonitis. Pneumonia and disseminated infections including meningitis, endocarditis, and cerebritis rarely have been reported. Optimal treatment of acremonium infections is not well defined both because infections due to these organisms are rare, and because many reports antedate effective antifungal therapy. In addition, susceptibility testing of filamentous fungi is poorly standardized, and in vitro sensitivity may not correlate with clinical response. Based on anecdotal reports, treatment of most invasive acremonium infections requires a combination of surgical intervention, when possible, and a regimen of amphotericin B. Some azoles also display inhibitory activity. Until more details are available regarding susceptibility of these organisms to antifungal agents, amphotericin B is recommended as initial therapy with the addition of either ketoconazole or fluconazole in infections of a life-threatening nature.

Utility of Gram's and Giemsa stains in the diagnosis of pulmonary tuberculosis

Conflicting information in the literature regarding the staining properties of Mycobacterium tuberculosis using Gram's stain and experience in two patients with pulmonary tuberculosis in whom the diagnosis was suspected after staining with non-acid-fast bacillus stains prompted the study of Gram's stain in this disease. The main finding was that mycobacteria appear as refractile, gram-neutral, or faintly gram-positive bacilli after Gram's stain, depending upon the plane of focus in which the organisms are regarded. It is concluded that the diagnosis of mycobacterial disease may be suggested by Giemsa- and Gram-stained smears of clinical specimens. M. tuberculosis may be either gram-neutral or gram-positive.

Solution hybridization and enzyme immunoassay for biotinylated DNA-RNA hybrids to detect enteroviral RNA in cell culture

A non-isotopic hybridization assay is described for detection of enteroviral RNA in cell culture. Two biotin-labelled cDNA probes, corresponding to 1 kb from the 5' end and 3.5 kb from the 3' end of the coxsackievirus B3 genome, were hybridized in solution with protease and detergent-treated cell culture suspensions. Labelled DNA-RNA hybrids were captured on microtiter plates coated with anti-biotin antibody and bound hybrids were measured with a beta-galactosidase-labelled monoclonal antibody specific for DNA-RNA hybrids. Coxsackie B3 was detected at a concentration of 500 pfu ml-1. The limit of detection for other enteroviruses ranged from 10(3.3) to 10(5.8) pfu ml-1. The enteroviruses that could be detected included coxsackie B1 and 3, coxsackie A1-6 and 15, poliovirus types 1-3, and enteroviruses 7, 11, and 71. ECHO 22 was the only enterovirus, of those that were tested, that could not be detected. The solution hybridization reaction and enzyme immunoassay for DNA-RNA hybrids does not require the use of radiolabelled probes or extraction of RNA with phenol. The assay yields a quantitative endpoint, which avoids the subjectivity inherent in membrane-based methods. These features would make the assay more adaptable to clinical laboratories than other formats which have been devised for measurement of viral RNA.

Ganciclovir treatment of serious cytomegalovirus infection in heart and heart-lung transplant recipients

Experience with ganciclovir treatment of life- or sight-threatening cytomegalovirus (CMV) infections in 22 heart and heart-lung transplant recipients at six medical centers was reviewed. All six heart-lung recipients and six of 16 heart recipients had CMV pneumonitis; five heart recipients had CMV gastrointestinal disease, three had retinitis, and two had infections in more than one organ system. Of the 18 patients (82%) surviving initial ganciclovir therapy, 16 improved, one stabilized, and one showed no change in clinical status. All cultures positive for CMV before treatment became negative during therapy. Six patients (33% of survivors) had recurrent episodes and received additional therapy. Four patients (18%) died during initial therapy; death was believed to be related to CMV infection in only two cases and to ganciclovir treatment in no case. Adverse reactions possibly attributable to ganciclovir included neutropenia (four patients), impaired renal function (one), thrombocytopenia (one), decreased blood pressure (one), and seizure (one). Ganciclovir appears to be well tolerated and to alter favorably the outcome of serious CMV infection in this patient population.

Pancreatoblastoma in a neonate with Wiedemann-Beckwith syndrome

The association of pancreatoblastoma and Wiedemann-Beckwith syndrome has not been noted previously. In this report we describe a child with Wiedemann-Beckwith syndrome who had a pancreatoblastoma resected on day 27 of life. He is also the first reported case of Wiedemann-Beckwith syndrome in a black baby.

Menetrier's syndrome in children

Since Menetrier's original description in 1888 many cases of hypertrophic gastritis have been recorded in adults. Only recently has a similar syndrome been described in childhood. The case reported demonstrates the characteristic features of the condition (the duration was rather longer than in other reported cases) and diagnosis, clinical course and aetiology are discussed. In contrast to the adult disease this illness is usually short-lived with full clinical and histological remission occurring within a few months.