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Biomedical subjects

S Bansal

Publications and source records attributed to S Bansal.

At least 73 records · Page 4Linked to original sources

Radiology performed by nonradiologists in the United States: who does what?

OBJECTIVE: When nonradiologists perform radiologic procedures, rather than referring their patients to radiologists, utilization--and therefore costs--are high, and quality appears often to be poor. In light of these public policy concerns, the American College of Radiology developed a detailed descriptive analysis of radiology performed by nonradiologists. MATERIALS AND METHODS: Medicare data from 1989, which make up a uniform record of one third of the nation's health care, were the source of the information. These data are reasonably, although not exactly, representative of patients of all ages. We measured radiologic work, and nonradiologists' share of it, in professional component relative value units, using the Medicare radiology relative value scale. RESULTS: Nonradiologists performed 25% of all radiologic work in the United States; their share was 46% in offices and freestanding centers, 27% for hospital inpatients, and 8% for outpatients. Counting procedures (rather than work measured in relative value units), nonradiologists' share was 64% in offices and freestanding centers and 8% for inpatients. Nonradiologists performed two thirds of all work in sonography, half of interventional radiology/angiography, 15-17% of general radiology and nuclear medicine, and a few percent of CT/MR and radiation oncology. Cardiologists performed 10% of all radiologic work in the United States; internists 5%; and orthopedists, ophthalmologists, and family and general practitioners, 2% each. Almost half of radiologic work performed by nonradiologists consisted of coronary angiography and cardiac sonography, done principally by cardiologists. Radiologists do less than 5% of this work. Office and freestanding center general radiology, performed mostly by orthopedists and primary care physicians, accounted for one fourth of the radiologic work done by nonradiologists. CONCLUSION: The general radiology performed by nonradiologists is of a magnitude that easily could be transferred to radiologists, particularly because many unnecessary imaging studies would most likely be eliminated as a result. Such a transfer would reduce costs and probably improve quality but might sometimes decrease patient convenience. However, because many radiologists do not perform coronary angiography and cardiac sonography, a transfer of these responsibilities to radiologists would be problematic and likely to require extensive additional training of radiologists.

Diagnostic Imaging↗

Primary sequence and location of the idiotopes of V-88, a DNA-binding monoclonal autoantibody, determined by idiotope scanning with synthetic peptides on pins.

In this study, the primary sequence and location of the idiotopes of monoclonal antibody (mAb) V-88 have been examined. V-88 was derived from an adult (NZB x NZW)F1 mouse, has been partially defined previously with polyclonal anti-idiotype antisera, and is a member of the 16/6 idiotype (Id) family. From the inferred primary amino acid sequence of the antibody, sets of hexapeptides, overlapping by five residues, were synthesized on pins and used to scan the expression of epitopes (idiotopes) in the V regions of the light and heavy chains. A heterologous rabbit antiserum raised against the native antibody V-88, and absorbed to make it idiotype specific, was found to react with eight major epitopes distributed between the VH and VL regions. Half of these determinants mapped to the complementarity determining regions, with the others in framework sequences. Thus, the idiotype of antibody V-88 comprises, at least in part, continuous linear idiotopes in both hypervariable and framework areas. The process of absorbing the anti-idiotype antiserum on normal mouse immunoglobulin removed much of the background antibody activity against V region peptides, but left the activity against the dominant idiotopes. The sequence of a major idiotope, VATISG, in the FW2/CDR2 VH region is homologous to sequences of human antibodies that express the 16/6 idiotype, suggesting that Id.16/6 is at least in part defined by this region of the antibody. The same VH area is also homologous to sequences in bacterial and mammalian heat-shock proteins (hsp60-65). Thus there may be a functional link through idiotype connections, especially those involving Id.16/6, between anti-bacterial responses and production of autoantibodies, and some bacterial antigens may function indirectly as superantigens for B cells.

Amino Acid Sequence↗

A peptide from Schumanniophyton magnificum with anti-cobra venom activity.

Using the chick biventer cervicis preparation as a bioassay for antivenom activity, a peptide has been isolated from the aqueous extract of the bark of Schumanniophyton magnificum. The peptide was isolated and purified by a combination of reverse-phase and exclusion column chromatography, preparative TLC, and HPLC. The peptide has a relative molecular mass of about 6000 daltons and is similar in amino acid composition to the cardiotoxins present in snake venom. The isolated peptide showed dose-related inhibitions of the effects of cardiotoxin and total venom of cobra species using the chick biventer cervicis preparation.

Animals↗

Operational, professional, and business characteristics of radiology groups in the United States.

To learn the main operational, professional, and business characteristics of U.S. radiology group practices, researchers at the American College of Radiology surveyed these groups. Major findings included the following: Approximately 30% of groups provide only diagnostic radiologic services, a similar percentage provides only radiation therapy for oncologic patients, and the remainder provides both types of services. Forty-one percent of groups practice only in hospitals, 11% practice only in an office, and 48% practice in both settings. Diagnostic-only practices average 10,000-12,000 procedures per full-time equivalent radiologist per year. Groups typically require new members to be part of the group for almost 3 years before they become full partners. Formal call schedules are nearly universal among radiology groups. Groups are becoming increasingly involved with health maintenance organizations and other "alternative delivery systems," but fee-for-service remains by far the dominant source of groups' revenue. Most studied characteristics of groups are changing relatively slowly, and trends are generally toward increasing formalization of arrangements.

Age Factors↗

Hospital and office practices of radiology groups.

To obtain information on the characteristics and practices of radiology groups in the United States, the American College of Radiology conducted a group practice survey in 1989; this report presents the main survey findings about the office and hospital practices of such groups. A questionnaire and one follow-up were mailed to all 2,591 radiology groups in the United States. Responses were weighted to reflect all groups. Hospital practices averaged 0.7 diagnostic radiologic procedures (including outpatient procedures) per patient day, with little variation by hospital type. Magnetic resonance (MR) imaging and angioplasty procedures were concentrated in teaching hospitals, but this was not true of other sophisticated procedures such as computed tomography and nuclear medicine. Offices averaged 15,000 diagnostic examinations annually, with less variation than expected according to group size. In both hospitals and offices, more than 90% of technologists were registered. Outsiders (most often, referring physicians and hospitals) had a financial interest in half of all offices. MR imaging and mammography grew faster than any other examinations, but only 44% of hospital practices accepted nonreferred patients for mammography.

Ambulatory Care↗

Volunteer bias in a study of male alcoholics' sexual behavior.

Studies on sexual behavior frequently require that subject volunteers engage in intrusive/sensitive assessment procedures. While earlier investigators have found that these demands may result in volunteer bias (volunteers differing from nonvolunteers), these studies were limited to nonclinical samples. The present study involved 182 males admitted to an inpatient alcoholism rehabilitation program. Those patients who volunteered to participate in an intrusive study examining sexual functioning were dissimilar to nonvolunteers. Compared to nonvolunteers, volunteers reported a greater interest in sex, less satisfaction with sex, more concerns about sexual functioning, a greater incidence of premature ejaculation, and a greater incidence of negative sexual experience. Volunteers also had a higher MAST score, used outpatient substance-abuse counseling more often, and more frequently had a diagnosis of cocaine/amphetamine dependence and cannabis dependence. These differences between volunteers and nonvolunteers suggest a need to use caution when generalizing the results of similar studies to the overall population. Procedures that may help to minimize volunteer bias are offered.

Adult↗

Possible hypothalamic impotence. Male counterpart to hypothalamic amenorrhea?

Twenty-one men with erectile complaints who were found to have a low level of serum testosterone without a reciprocal elevation of the serum levels of luteinizing hormone were evaluated to identify whether the defect was of hypothalamic or of pituitary origin. Patients underwent a luteinizing hormone (LH)-follicle-stimulating hormone (FSH)-releasing hormone stimulation test that showed a normal but sluggish increase in LH and FSH levels, thus ruling out a pituitary defect and suggesting a suprapituitary abnormality. This was confirmed when, in response to clomiphene, patients had a normal increase in gonadotropin and testosterone levels. Although the basal as well as clomiphene and gonadotropin releasing hormone-stimulated levels of total testosterone and gonadotropins were identical in men less than and more than fifty years old, the elevation of free testosterone levels in response to clomiphene was higher in patients younger than fifty. This suggested that although the primary abnormality found in these patients is altered secretion of gonadotropin hormone-releasing hormone from the hypothalamus, an age-related decline in the responsivity of Leydig cells to LH may make it more manifest in older patients. Elevation of testosterone levels from a subnormal to a normal range in response to clomiphene administered for seven days suggests that the defect is functional and reversible and that the drug may be useful in treatment of sexual dysfunction in this group of patients.

Aging↗

The volume and cost of radiologic services in the United States in 1990.

Knowing the total number of radiologic services provided in the United States and their cost is important. This information can, for example, indicate the opportunities available to a radiology practice considering opening a new office or show whether high-technology radiology is, as is widely assumed, an important factor in United States health costs. However, neither the total number of procedures nor their cost is known. We developed two largely independent estimates of each total (one based principally on surveys of radiologists, the other on Medicare data) to cross-validate the estimates and provide an indication of their uncertainty. We estimate that 260-330 million radiologic procedures were performed in the United States in 1990 (including both diagnostic and therapeutic procedures and radiologic procedures performed by nonradiologists) and that payments for these services totaled $19 to $22 billion (including payments for technical components in the hospital setting). This total was approximately 3.5% of national spending on personal health care; high-technology radiology totaled less than half of this amount. The procedures numbered 1.0-1.3 per capita annually, an increase of some 10-40% since 1980. Of the spending total, $10 to $12 billion was paid to physician practices, with a substantial portion of this amount going ultimately to practice expenses, particularly in the office setting. Our results suggest that spending on high-technology radiology is too small to be a major explanation for the current level of health costs in the United States.

Costs and Cost Analysis↗

A new TSH assay. Just another technique or a useful test?

The immunoradiometric assay is a sensitive test for diagnosing thyroid dysfunction. It permits greater accuracy by measuring response of thyrotropin-producing cells of the pituitary to thyroxine (T4) as opposed to comparing circulating T4 to a range of values from healthy controls. The assay allows improved precision in establishing replacement and suppressive doses of hormone for thyroid disease.

Humans↗

Propylbenzilylcholine mustard labels an acidic residue in transmembrane helix 3 of the muscarinic receptor.

Muscarinic acetylcholine receptors were purified from rat forebrain and labeled with [3H]N-(2-chloroethyl)N-(2',3'-[3H2]propyl)-2-aminoethylbenzilate. Cleavage of the labeled muscarinic acetylcholine receptors with a lysine-specific protease yielded labeled, glycosylated peptides about 130 and 200 residues in length, which came from different receptor sequences. The probable cleavage sites are in the second intracellular loop and in the second extracellular or third intracellular loop. The N-terminal 130 residues are disulfide-bonded to another part of the receptor structure, supporting the presence of a link between the second and third extracellular loops. The [3H]propylbenzilylcholine mustard-receptor link is cleaved by nucleophiles, acids, and bases under denaturing conditions, suggesting modification of an acidic residue. Cyanogen bromide cleavage points to transmembrane helix 3 as the site of label attachment.

Animals↗

Effect of yohimbine hydrochloride on erectile impotence: a double-blind study.

A double-blind, partial crossover study on the therapeutic effect of yohimbine hydrochloride on erectile dysfunction was done in 82 sexually impotent patients. All patients underwent a multifactorial evaluation, including determination of penile brachial blood pressure index, cavernosography, sacral evoked response, testosterone and prolactin determination, Derogatis sexual dysfunction inventory and daytime arousal test. After 1 month of treatment with a maximum of 42.0 mg. oral yohimbine hydrochloride daily 14 per cent of the patients experienced restoration of full and sustained erections, 20 per cent reported a partial response to the therapy and 65 per cent reported no improvement. Three patients reported a positive placebo effect. Maximum effect takes 2 to 3 weeks to manifest itself. Yohimbine was active in some patients with arterial insufficiency and a unilateral sacral reflex arc lesion, and in 1 with low serum testosterone levels. The 34 per cent response is encouraging, particularly in a Veterans Administration population presenting with a high incidence of diabetes and vascular pathological conditions not found in regular office patients. Only few and benign side effects were recorded, which makes this medication worth an attempt, often as a first line of treatment even at a dose of 8 tablets.

Adult↗

A comparison of nocturnal penile tumescence and penile response to erotic stimulation during waking states in comprehensively diagnosed groups of males experiencing erectile difficulties.

The erectile responses of 13 nondysfunctional males and 48 dysfunctional males were compared during Nocturnal Penile Tumescence (NPT) and during exposure to erotic videotapes. The results showed distinct patterns of NPT and daytime responding that could differentiate the various subgroups: those displaying (i) no dysfunction; (ii) vasculogenic erectile dysfunction; (iii) high risk for erectile dysfunction (organic and psychogenic); (iv) psychogenic dysfunction; reactive to erotica; and (v) psychogenic dysfunction; nonreactive to erotica. Subjects participating in this study underwent a comprehensive medical and psychological screening to place them in each subgroup. The penile circumference response to erotic stimuli used in conjunction with NPT response appeared useful in differentiating subgroups of erectile dysfunction and suggested the need for further diagnostic refinement in this area. The majority of vasculogenic dysfunctional subjects experienced greater erection responses during exposure to erotic stimulation than during NPT; several of these subjects achieved almost full erections in waking states but were practically flaccid at night. The discussion covers diagnostic and therapeutic implications.

Adult↗

Sexual dysfunction in hypertensive men. A critical review of the literature.

Sexual dysfunction is common in hypertensive men and often is first reported by patients while receiving hypotensive therapy, leading to a widespread belief by patients and physicians that the sexual dysfunction is caused by a specific antihypertensive medication. However, it is unclear from the literature whether this problem is related to hypertension or to its therapy. Further, whether the erectile failures reported during therapy are a result of 1) reduced penile blood flow secondary to reduction of blood pressure after antihypertensive treatment or to obstructive vascular disease (or both) or 2) specific drug effects has not been well studied. Because of these unresolved issues, this common problem is not well managed and contributes to noncompliance with therapy by hypertensive male patients, which impedes the attainment of satisfactory blood pressure control. The present article reviews the literature related to hypertension and sexual function in men and outlines a management strategy for clinicians that attempts to document normalcy of sexual function before initiating treatment in newly diagnosed hypertensive patients. Further, it does not ascribe causality to specific antihypertensive agents for the sexual dysfunction reported by treated hypertensive patients but attempts instead to delineate the pathogenesis of the dysfunction. Once the pathogenesis is established, treatment plans can be implemented to restore normotension and maintain adequate sexual function among treated hypertensive men. The article also discusses how applied research in this area may be performed.

Adult↗

Hemoptysis during sexual intercourse. Unusual manifestation of coronary artery disease.

Sexual activity increases physiologic demands on the cardiovascular system. A patient with stable angina pectoris experienced recurrent bouts of hemoptysis caused by left ventricular failure that occurred only during sexual activity. Severe atherosclerotic coronary vascular disease was confirmed by cardiac catheterization. The patient underwent successful coronary artery bypass grafting; nine months after surgery, he is sexually active and symptom-free.

Aged↗

Some unusual periorbital dermatoses.

Three case reports of primary periorbital dermatitis are presented. The etiology of these were molluscum contagiosum, Microsporum canis, and Coccidioides immitis. In each case, the presenting complaint was unusual since the primary lesion started in the periorbital region.

Adult↗

Deep-penile-vein arterialization for arterial and venous impotence.

Eleven impotent men underwent deep-penile-vein arterialization after preoperative assessment by a multidisciplinary team. Penile Doppler pressures, testosterone levels, and nocturnal penile tumescence were used to establish a vasculogenic etiology. Cavernosography, artificial erection by saline infusion, and selective hypogastric arteriography were obtained to delineate whether arterial, venous, or mixed (arterial/venous) factors predominated. Penile revascularization consisted of femoral artery to deep-penile-vein saphenous bypass, with ligation of superficial veins at the base of the penis in patients with venous leakage. Cumulative graft patency was 91% up to 20 months. There were no deaths. The average preoperative flow requirement of values greater than 250 mL/min was reduced to 59 mL/min postoperatively. Follow-up results of nocturnal penile tumescence were excellent in four of four patients with venous (venous leakage), two of three patients with arterial, and one of four patients with mixed factors. Deep-penile-vein arterialization appears to be beneficial for impotence secondary to venous leakage, with inconsistent results for arterial and mixed factors.

Adult↗

Effects of medroxyprogesterone acetate on subjective arousal, arousal to erotic stimulation, and nocturnal penile tumescence in male sex offenders.

Three chronic pedophiliac sex offenders were treated individually with medroxyprogesterone acetate (MPA) over a minimum of 3 months. Genital and subjective response to erotic stimulation, nocturnal penile tumescence, self-reporting of sexual urges, and testosterone levels were recorded repeatedly throughout the study. A single-subject reversal design was used and medication was administered through a double-blind procedure. The results showed that self-report of arousal outside of a laboratory setting was unreliable as a measure of the drug effect. In a laboratory setting, however, there appeared to be a significant reduction in the report of arousal to erotic stimuli while genital arousal decreased only slightly. Reversal of these responses occurred in only one subject during a final placebo phase. Nocturnal penile tumescence was significantly decreased during MPA administration and appeared to be related to decreases in total testosterone.

Adult↗