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W J Hellstrom

Publications and source records attributed to W J Hellstrom.

At least 19 recordsLinked to original sources
PubMed2004

The penile implant for erectile dysfunction.

INTRODUCTION: Penile prostheses, introduced as the first effective organic treatment for erectile dysfunction over three decades ago, have an important role in the treatment of erectile dysfunction when other nonprosthetic treatment options have proven unsatisfactory. Although they are the least chosen and most invasive treatment option, they have the highest satisfaction rate of all available ED options and provide a predictable and reliable result. AIM: To provide recommendations/guidelines concerning state-of-the-art knowledge for utilization of the penile prosthesis in the management of men with erectile dysfunction. METHODS: An International Consultation in collaboration with the major sexual medicine associations assembled over 200 multidisciplinary experts from 60 countries into 17 committees. Committee members established specific objectives and scopes for various sexual medicine topics. The recommendations concerning state-of-the-art knowledge in the respective sexual medicine topic represent the opinion of experts from five continents developed in a process over a 2-year period. There were 10 experts from seven countries concerning the Penile Implant for Erectile Dysfunction. MAIN OUTCOME MEASURE: Expert opinion was based on grading of evidence-based medical literature, widespread internal committee discussion, public presentation and debate. RESULTS: Recommendations/guidelines for penile prosthesis (hydraulic, semi-rigid and soft silicone) insertion for management of men with erectile dysfunction were updated. Consensed issues included: criteria for patient selection, informed consent procedures, strategies for preoperative preparation, operative incisions/technical considerations and outcome results in terms of patient satisfaction and device survival. Updated information was reviewed concerning therapies for device failures, device insertion in scarred corporal bodies and strategies for managing implant infections. CONCLUSIONS: There is a need for more research in developing management strategies for insertion of penile prostheses in men with ED.

Consensus↗
PubMed2001

Increased expression of arginase II in human diabetic corpus cavernosum: in diabetic-associated erectile dysfunction.

Nitric oxide (NO) is the principal mediator of penile erection. NO is synthesized by nitric oxide synthase (NOS). It has been well documented that the major causative factor contributing to erectile dysfunction in diabetic patients is the reduction in the amount of NO synthesis in the corpora cavernosa of the penis resulting in alterations of normal penile homeostasis. Arginase is an enzyme that shares a common substrate with NOS, thus arginase may downregulate NO production by competing with NOS for this substrate, l-arginine. The purpose of the present study was to compare arginase gene expression, protein levels, and enzyme activity in diabetic human cavernosal tissue. When compared to normal human cavernosal tissue, diabetic corpus cavernosum from humans with erectile dysfunction had higher levels of arginase II protein, gene expression, and enzyme activity. In contrast, gene expression and protein levels of arginase I were not significantly different in diabetic cavernosal tissue when compared to control tissue. The reduced ability of diabetic tissue to convert l-arginine to l-citrulline via nitric oxide synthase was reversed by the selective inhibition of arginase by 2(S)-amino-6-boronohexanoic acid (ABH). These data suggest that the increased expression of arginase II in diabetic cavernosal tissue may contribute to the erectile dysfunction associated with this common disease process and may play a role in other manifestations of diabetic disease in which nitric oxide production is decreased.

Arginase↗
PubMed2001

Androgen deficiency in the aging male: pathophysiology, diagnosis, and treatment alternatives.

Androgen deficiency in the aging male is associated with negative effects on mood and cognition, diminished sexual function, and osteoporosis. The aging of our population, combined with an increased acceptance of medical technology, has focused greater attention on optimizing health during the "golden years." Androgen replacement therapy may remedy many of the deleterious consequences of hypogonadism. This communication reviews the clinical manifestations and diagnosis of androgen deficiency, the inherent risks and benefits of androgen replacement, and the options of testosterone replacement currently available.

Aging↗
PubMed2001

Intracavernosal injection and intraurethral therapy for erectile dysfunction.

Although the search for newer and more effective oral therapies is continually expanding, intracavernosal and intraurethral treatments continue to keep pace and are expected to remain in the clinician's armamentarium in the years to come. Unless there are contraindications, oral therapies are effective, have minimal side effects, and are first-line treatment. Some patients who have failed intraurethral and intracavernosal injection therapies previously have been shown to have successful outcomes with oral sildenafil in 56% to 57% of cases. If oral therapies are ineffective or have undesirable side effects, the intraurethral or intracavernosal routes are the next approach that should be prescribed.

Adrenergic alpha-Antagonists↗
PubMed2001

Evaluation of oral ro70-0004/003, an alpha1A-adrenoceptor antagonist, in the treatment of male erectile dysfunction.

Alpha-adrenoceptor antagonists have been used for the treatment of male erectile dysfunction (MED). Ro70-0004/003 (Ro70-0004) is a selective and orally active alpha1A-adrenoceptor antagonist. The objective of this study was to: (1) pharmacologically elucidate the alpha1-adrenoceptor subtype mediating norepinephrine-induced contraction of human isolated corpus cavernosal tissue and (2) conduct a clinical proof-of-concept study with Ro70-0004 to test the hypothesis that selective alpha1A-adrenoceptor blockade would improve erectile function in patients with MED. In vitro organ bath studies were conducted with strips of human isolated corpus cavernosal tissue obtained from patients undergoing penile prosthesis implantation. Prazosin, cyclazosin, RS-100329 and Ro70-0004/003 antagonized norepinephrine-induced contractile responses with affinity estimates (pK(B) or pA2) of 8.4, 7.3, 9.2 and 8.8, respectively, consistent with the singular involvement of alpha1A-adrenoceptor subtype. A clinical study (single center, observer-blind, randomized, placebo-controlled, extended period Latin-Square crossover design) was conducted in 24 male patients (mean age 44 y) with MED of no established organic cause to evaluate the efficacy of a 5-mg oral dose of Ro70-0004. The primary efficacy endpoint was the duration of rigidity > 60% at the base of the penis measured between 0.5 and 2.5 h post-dose. Rigidity was assessed by penile plethysmography using the RigiScan Plus device during visual sexual stimulation. The safety and efficacy of Ro70-0004 was also assessed. A 50-mg dose of sildenafil was included as a positive control. For the primary efficacy endpoint, the mean duration of erection was 9.69 min following administration of placebo, 8.28 min following Ro70-0004, and 22.64 min following sildenafil. Only the difference between sildenafil and placebo reached statistical significance (P < 0.05). A similar pattern was observed when measuring a duration of rigidity > 80% at the base of the penis (secondary endpoint). Ro70-0004 was safe and generally well tolerated (only two out of 20 patients reported at least one adverse event). The highly selective alpha1A-adrenoceptor antagonist, Ro70-0004, given at a single dose of 5 mg, did not improve erectile function when compared to placebo.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed2001

Long-term follow-up on use of pericardial graft in the surgical management of Peyronie's disease.

We have previously reported on the use of Tutoplast cadaveric pericardium as an alternative material for grafting the tunica albugineal defect after Peyronie's plaque excision with satisfactory results in 11 patients. We now review long-term outcomes in this cohort of men. Eleven patients with significant penile curvature interfering with sexual intercourse were evaluated after at least 12 months of conservative therapy. All patients underwent pre-operative evaluation, including penile duplex Doppler ultrasound studies. Chemically processed and gamma-irradiated pericardium (Biodynamics International, Parsippany, NJ) was used to graft the cavernosal defect after surgical excision of the penile plaque. Three patients simultaneously underwent placement of penile prostheses secondary to documented erection problems identified at duplex Doppler ultrasound evaluation. The long-term postoperative complications and erectile function were evaluated with a mean follow-up of 30 months (range 25-35 months). All patients reported resolution of penile curvature allowing for normal sexual function after a mean follow-up of the first 14 months. Thirty months after placement of cadaveric pericardium, the three prosthetic patients still reported excellent sexual function. For the eight patients who did not undergo placement of a prosthesis, three with small to medium plaque size (<2 x 5 cm) continued to do well. The remaining five patients with a large plaque size (>2 x 5 cm) did well initially, but later reported difficulty maintaining erection due to venous leakage, thus they are currently using either a vacuum constriction device or an Actis ring. Three out of these five venous leakage patients had ventral plaques; two had dorsal plaques, one of significant size (4 x 5 cm). We conclude that for those patients who do not undergo placement of a prosthesis, a better long-term outcome is observed when the plaque is small to medium in size (<2 x 5 cm) and dorsally located. Patients with ventral plaque, extreme curvature, or plaque size >4 x 5 cm were more likely to have venoocclusive dysfunction, necessitating further intervention.

Aged↗
PubMed2001

Role of genitourinary inflammation in infertility: synergistic effect of lipopolysaccharide and interferon-gamma on human spermatozoa.

Pro-inflammatory cytokines are elevated in the semen of patients with genitourinary inflammation (GUI). Whether this increase in cytokines in GUI patients plays any critical role in male factor infertility is not clear. The present study investigated the in vitro effects of two important pro-inflammatory cytokines, lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), on sperm motility, viability, membrane integrity and motion parameters. Washed spermatozoa from healthy donors were incubated with LPS (0.1 mg/mL) or IFN-gamma (0.1 mg/mL) alone or in combination. Sperm motility, viability, membrane integrity and computer-assisted motion were evaluated at various time intervals (0, 30, 60 and 180 min) after treatment. Sperm membrane integrity was analysed using the hypo-osmotic swelling test (HOST). LPS and IFN-gamma individually did not alter sperm viability or motility, but their combination showed a significant time-dependent decrease (p < 0.05) in sperm motility, viability and membrane integrity. Sperm motion parameters (straight-line velocity, curvilinear velocity, mean linearity, or amplitude of lateral head displacement) were not affected by LPS or IFN-gamma at the concentrations used in this study. These data suggest that the combination of LPS and IFN-gamma is detrimental to human spermatozoa and may contribute to male factor infertility in patients with chronic GUI.

Cell Membrane↗
PubMed2001

Gene transfer of prepro-calcitonin gene-related peptide restores erectile function in the aged rat.

Erectile dysfunction in the aging male is caused, in part, by inadequate relaxation of the corpora cavernosal smooth musculature. Calcitonin gene-related peptide (CGRP), a peptide neurotrasmitter localized in the corpora cavernosa, is down-regulated in the aging rat penis. We examined the hypothesis that this reduction in CGRP may contribute to decreased cavernosal smooth muscle relaxation. Therefore, we sought to determine whether adenoviral-mediated gene transfer of prepro-CGRP (AdRSVCGRP) could enhance erectile responses in aged rats. We found a significant decrease in CGRP concentrations and in cAMP and cGMP levels in aged rat cavernosal tissue compared to younger rats. Aged rats also had significantly lower erectile function as determined by cavernosal nerve stimulation compared to younger rats. Five days after transfection with AdRSVCGRP, these aged rats had an approximately threefold increase in cavernosal CGRP levels compared to animals transfected with adenoviruses encoding nuclear-targeted beta-galactosidase (AdRSV beta gal). The AdRSVCGRP-transfected animals also demonstrated an increase in CGRP mRNA and immunohistochemical localization of CGRP in the smooth muscle of the corpora cavernosa. In addition, cAMP levels in the corpora cavernosa were significantly increased, whereas cGMP levels remained unchanged. Adenoviral transduction efficiency of beta-galactosidase reporter gene was measured by chemiluminescence and was observed in cavernosal tissue 5 days after transfection with AdRSV beta gal. More importantly, 5 days after administration of AdRSVCGRP, a significant increase was observed in the erectile response to cavernosal nerve stimulation in the aged rat, similar to the response observed in younger rats. These data suggest that in vivo adenoviral gene transfer of CGRP can physiologically improve erectile function in the aged rat.

Adenoviridae↗
PubMed2001

Direct effects of selective type 5 phosphodiesterase inhibitors alone or with other vasodilators on the erectile response in cats.

PURPOSE: Zaprinast, dipyridamole and sildenafil were injected into the corpora cavernosa of cats to determine whether changes in the steady state level of cyclic guanosine monophosphate (cGMP) induced by inhibiting type 5 phosphodiesterase would cause an erectile response. MATERIALS AND METHODS: Increases in intracavernous pressure, penile length and erectile response duration were determined after intracavernous injection of the type 5 cGMP specific phosphodiesterase inhibitors zaprinast, dipyridamole and sildenafil as well as combined zaprinast and prostaglandin E1 (PGE1), and zaprinast and sodium nitroprusside. Systemic arterial pressure was concurrently assessed in these experiments. All responses to phosphodiesterase inhibitors were compared to a control triple drug combination of 1.65 mg papaverine, 0.5 microg PGE1 and 25 microg phentolamine. RESULTS: Each selective type 5 phosphodiesterase inhibitor caused dose related increases in intracorporeal pressure and penile length. However, none of the compounds was as effective as the control drug combination of papaverine, phentolamine and PGE1. Combining zaprinast with sodium nitroprusside led to further increases in pressure and erectile response duration that more closely resembled the control drug response. Combining zaprinast with PGE1 led to a response that was indistinguishable from the control response. CONCLUSIONS: The results of these feline studies establish that administering a type 5 phosphodiesterase inhibitor without concomitant administration of a nitric oxide donor or stimulation of the cavernous nerves may have a direct effect on the erectile response. These data also suggest that combining a selective type 5 phosphodiesterase inhibitor with PGE1 may be highly effective local therapy for erectile dysfunction and an acceptable alternative to other current forms of treatment.

Alprostadil↗
PubMed2001

Combined intralesional interferon alpha 2B and oral vitamin E in the treatment of Peyronie's disease.

It has been recently reported that intralesional therapy with alpha interferon 2B resulted in significant improvement of both objective and subjective complaints (penile curvature, pain, plaque size, sexual function) associated with Peyronie's disease. Vitamin E, with its antioxidant properties, may play a role in reducing the inflammatory response. This study was designed to determine the safety and effectiveness of a high dose of alpha INF-2B injected weekly into the Peyronie's plaque combined with oral Vitamin E therapy. Twenty-nine patients with Peyronie's disease were evaluated with penile duplex Doppler for degree of penile curvature, deformity, and plaque size both prior to and after treatment. Each patient then received 4.0 x 10(6) units of alpha INF-2B in 10 cc of normal saline after appropriate local anesthesia. Injections were given once per week directly into the Peyronie's plaque for a period of 10 weeks. Patients also received 400 units of Vitamin E by mouth twice a day. Subjective data was obtained via a questionnaire prior to and at the conclusion of the study. Preliminary results demonstrated improvement of penile curvature in 39% of patients, with one patient experiencing complete resolution. Significant decreases in plaque sizes were noted in 11 of these patients, with softening of the plaques noted in all patients completing the study. Seven patients dropped out of the study prior to completing the 10 weeks: three with severe disease proceeded to surgery, two were lost to follow-up, one had exascerbation of his arthritis symptoms, and one quit secondary to flu-like symptoms. Subjective data from questionnaires revealed improvement in sexual function in those men with decreased curvature and plaque size. Weekly intralesional injections with 4.0 x 10(6) units improved plaque consistency and decreased curvature and plaque size (P < 0.5). Overall subjective sexual performance was reportedly improved. Increased dosage of alpha INF-2B resulted in increased severity of flu-like symptoms when compared to the lower (1 x 10(6) units) biweekly dosage. No significant difference was noted with the addition of oral Vitamin E therapy.

Adult↗
PubMed2000

Evaluation of cadaveric pericardium in the rat for the surgical treatment of Peyronie's disease.

OBJECTIVES: To evaluate the intermediate-term efficacy of cadaveric pericardium (Tutoplast) as a grafting material in the surgical correction of Peyronie's disease using a rat model. Peyronie's disease is a connective tissue disorder of the tunica albuginea. When less invasive modalities fail to correct the penile deformity, surgical excision of the plaque and coverage with various grafting materials has been advocated. MFETHODS:Twenty male Sprague-Dawley rats (300 to 325 g) constituted the study population. The animals were divided into two groups: group 1, control rats (n = 10) and group 2, rats that underwent wedge excision of the tunica albuginea and replacement with cadaveric pericardial grafts (n = 10). All rats underwent electrical stimulation of the cavernosal nerve to assess erectile function after 4 months. Tissues obtained after death were stained with trichrome and Verhoff's van Giesen for collagen and elastic fibers. RESULTS: Erectile function as studied by cavernosal nerve stimulation was not significantly different in either group (P >0.05), and histologic studies of penile cross sections of the pericardial graft group revealed a mild to moderate degree of fibrosis surrounding the patch at 4 months. CONCLUSIONS: We found that pericardial cadaveric grafts in a rat model are a suitable tunica albuginea substitute. They allow for penile expansion after cavernosal nerve stimulation and are strong enough to withstand normal intracorporeal pressures. Our early experimental data in the rat support the use of pericardial cadaveric material for coverage of excised Peyronie's plaques. However, long-term follow-up in humans is mandatory.

Adult↗
PubMed2000

Nitric oxide-mediated erectile effects of galantide but not galanin in vivo.

The purpose of this study was to investigate the in vivo effects of intracavernosal injections of galanin and galantide (a specific galanin receptor antagonist) on penile erection in the anesthetized cat. Erectile responses to galanin and galantide were compared with responses to a standard triple drug combination [1.65 mg papaverine, 25 microg phentolamine, and 0.5 microg prostaglandin E(1) (PGE(1))]. Intracavernosal injections of galanin (3-100 nmol) and galantide (0. 1-3 nmol) induced penile erection in a dose-dependent manner. In terms of relative potency, galantide was approximately 100-fold more potent than galanin at increasing cavernosal pressure. The maximal increases in intracavernosal pressure in response to galanin and galantide were 83 and 95%, respectively, of the control triple drug combination. The total durations of erectile response caused by these peptides were significantly shorter (P<0.05) than those by the triple drug combination. The nitric oxide synthase inhibitor L-NAME (20 mg) significantly decreased the erectile response in the cat to galantide but not to galanin, while the K(+)(ATP) channel antagonist U-37883A (3 mg) had no effect on the erectile response to galanin nor galantide. The results of the present study demonstrate that galantide, a putative antagonist for the galanin receptor, has more potent agonist activity than galanin in increasing intracavernosal pressure in the cat. Moreover, these data suggest that galantide, but not galanin, causes penile erection by an NO/cGMP-dependent mechanism. This is the first study to demonstrate that galanin may play a role in the physiology of penile erection.

Animals↗
PubMed2000

Peyronie's disease: advances in basic science and pathophysiology.

Peyronie's disease is an idiopathic, localized connective tissue disorder of the penis that involves the tunica albuginea of the corpus cavernosum and the adjacent areolar space. The tunica albuginea plays an important role in the mechanism of erection. Peyronie's disease is characterized by local changes in the collagen and elastic fiber composition of the tunica albuginea. The formation of fibrotic plaques alters penile anatomy and can cause different degrees of bending, narrowing, or shortening of the penis. Moreover, a significant number of men with Peyronie's disease develop erectile dysfunction. Penile blood flow studies in many patients with Peyronie's disease suggest a strong association with veno-occlusive dysfunction. Although long recognized as an important clinical entity of the male genitalia, the etiology of this disease has remained poorly understood. The following review focuses on recent research on the pathophysiology of Peyronie's disease.

Animals↗
PubMed2000

Pharmacotherapy for erectile dysfunction.

Erectile dysfunction (ED) is defined as the consistent inability to obtain or maintain an erection for satisfactory sexual relations. An estimated 20-30 million men suffer from some degree of sexual dysfunction. The past 20 years of research on erectile physiology have increased our understanding of the biochemical factors and intracellular mechanisms responsible for corpus cavernosal smooth muscle contraction and relaxation, and revealed that ED is predominantly a disease of vascular origin. Since the advent of sildenafil (Viagra), there has been a resurgence of interest in ED, and an increase in patients presenting with this disease. A thorough knowledge of the physiology of erection is essential for future pharmacological innovations in the field of male ED.

Adrenergic alpha-Antagonists↗
PubMed2000

The effect of sildenafil on human sperm motion and function from normal and infertile men.

The aim of this report was to study the effect of sildenafil, a specific type-5 phosphodiesterase inhibitor, on human sperm motility, viability, membrane integrity and sperm penetration assay. Spermatozoa were obtained from normal donors (n = 6) and infertile men (n = 6) were washed using a single Percoll (80%) gradient, suspended in Ham's F-10 medium, and incubated with various doses of sildenafil (125, 250 and 750 ng/ml); pentoxifylline (3 mM) was used as a positive control, and Ham's F-10 was used as a reagent control. Sperm motility, grade, viability, membrane integrity (by hypo-osmotic swelling test), and motion evaluation were carried out at various time intervals. Hamster ova sperm penetration assay (SPA) was used to evaluate overall sperm function. Sildenafil did not affect sperm motility, viability or membrane integrity under these conditions as compared to our Ham's control (P> 0.05). Incubation with pentoxifylline significantly enhanced sperm motility (P < 0.05) and viability without affecting membrane integrity (P < 0.05). Sperm incubated with sildenafil and pentoxifylline from both normal donors and infertile patients demonstrated no significant change in sperm penetration assay from respective controls. In conclusion, sildenafil, at the doses evaluated, did not significantly alter the motility, viability, membrane integrity or sperm penetration characteristics of human spermatozoa from normal donors and infertile patients.

Animals↗
PubMed2000

Adenoviral gene transfer of endothelial nitric oxide synthase (eNOS) to the penis improves age-related erectile dysfunction in the rat.

Nitric oxide (NO) is the principal mediator of penile erection. NO is synthesized by a variety of nitric oxide synthases (NOS). It has been demonstrated that a decrease in NOS activity, as observed in aging, is associated with a diminished erectile response. The objective of this study was to determine if adenoviral-mediated gene transfer of eNOS could reverse age-related erectile dysfunction in the rat. Two groups of animals were transfected with adenoviruses: (1) aged rats (60 weeks) with AdRSVbetagal; and (2) aged rats (60 weeks) with AdRSVeNOS. Five days after transfection, these study animals underwent cavernosal nerve stimulation (CNS) to assess erectile function and their responses were compared with young (20 weeks) control rats. Cross-sections of the rat penises transfected with AdRSVeNOS were examined after trichrome staining. Adenoviral transduction efficiency of beta-galactosidase reporter gene was measured by a galacto-light chemiluminescent reporter gene assay in cavernosal tissues of rats administered AdRSVbetagal. The transgene expression of eNOS was examined by RT-PCR in rats transfected with AdRSVbetagal and AdRSVeNOS. eNOS and iNOS protein levels were measured by Western blot analysis, and cGMP levels were assessed in cavernosal tissue by enzyme immunoassay. Adenoviral expression of the beta-galactosidase reporter gene was observed in cavernosal tissue for up to 30 days, with peak expression registered at 5 days after intracavernosal administration of AdRSVbetagal. Cross-sections of the rat penises transfected with the AdRSVeNOS revealed no pathological (morphological or histological) changes. Five days after administration of AdRSVeNOS, eNOS protein, mRNA and cGMP levels in the corpora cavernosa were significantly increased (P<0. 05), while iNOS protein levels remained unchanged (P>0.05). In conclusion, enhanced expression of eNOS employing an adenoviral vector significantly increased the erectile response to cavernosal nerve stimulation in the aged rat, similar to the response observed in younger rats. These data suggest that in vivo adenoviral gene transfer of eNOS can physiologically improve erectile function in the aged rat.

Adenoviridae↗
PubMed2000

Application of pericardial graft in the surgical management of Peyronie's disease.

PURPOSE: We investigated the use of Tutoplast cadaveric pericardium as an alternative material for grafting the tunica albuginea defect after Peyronie's plaque excision. MATERIALS AND METHODS: A total of 11 patients with significant penile curvature interfering with sexual intercourse were evaluated after at least 12 months of conservative therapy. Preoperative evaluation in all cases included penile duplex Doppler ultrasound studies. Chemically processed and gamma irradiated pericardium was used to graft the cavernosal defect after surgical excision of the penile plaque. In 3 patients a penile prosthesis was simultaneously placed secondary to documented erectile dysfunction at duplex Doppler ultrasound evaluation. RESULTS: Penile curvature resolved in all patients, allowing for normal sexual function after a mean followup of 14 months (range 9 to 19). No postoperative evidence of tissue rejection or infection was noted. In 1 patient urethro-corporal communication developed and a single penile cylinder was explanted. Another patient had a mild dorsal bulge at the site of graft placement when the prosthesis was fully inflated. CONCLUSIONS: Polymeric silicone material used to provide satisfactory results in the surgical treatment of Peyronie's disease but it is no longer available for biomedical use. We demonstrate the effective use of cadaveric pericardium as a graft material for cavernosal defects after Peyronie's plaque excision. Overall patient satisfaction, absence of a second surgical incision, relative low risk and ease of surgical placement make this material ideal for the surgical treatment of this disease process.

Adult↗