Evaluation of renal transplant dysfunction by duplex Doppler sonography: a prospective study and review of the literature

A disconcertingly wide variation exists in the literature as to the accuracy of duplex Doppler sonography in the detection of acute renal transplant rejection. Sensitivities range from 9% to 76%. In an attempt to explain the disparity of results, we undertook a double-blind prospective study of the accuracy of duplex Doppler ultrasound in the detection of acute rejection in renal transplants. We scanned 49 consecutive patients with a total of 65 biopsies; 46 biopsies in 33 consecutive patients were included in our study. In our population, the prevalence of acute rejection was 61% (28/46). Using a resistive index (RI) cutoff of greater than 0.90 based on the main renal artery flow pattern, the sensitivity of our test was 43%, with a 67% specificity. The positive predictive value was 67%. Our results are contrasted and compared with the published data from other groups in a critical survey of the literature. We conclude that duplex Doppler sonography alone is inadequate to evaluate acute rejection in renal transplants.     

The role of target muscles in the expression of calcitonin gene-related peptide mRNA in the spinal nucleus of the bulbocavernosus.

Previous studies have shown that calcitonin gene-related peptide (CGRP) mRNA steady-state levels and CGRP immunoreactivity in motoneurons of the spinal nucleus of the bulbocavernosus (SNB) are inversely related to the gonadal steroid environment in male rats. Since both the SNB motoneurons and their target muscles, the bulbocavernosus and the levator ani, are steroid sensitive, gonadal steroids may act at either site to regulate CGRP expression. In the present study, we tested the hypothesis that gonadal steroids influence CGRP expression in SNB motoneurons through their effects on the bulbocavernosus and levator ani muscles. We determined the levels of alpha-CGRP mRNA and immunoreactive CGRP in SNB motoneurons of adult male rats following injection of the bulbocavernosus with muscle extracts from bulbocavernosus/levator ani of castrated rats, paralysis of the bulbocavernosus or pudendal nerve cuts. Following injection of the bulbocavernosus/levator ani with extracts from castrated rats, the level of CGRP expression and the number of SNB motoneurons with alpha-CGRP message were increased. These studies suggest that the bulbocavernosus/levator ani muscles from castrated rats produce a factor that increases levels of CGRP. Injections of extract prepared from the bulbocavernosus and levator ani muscles of gonadally intact rats did not change the expression of alpha-CGRP mRNA in the SNB. Paralysis of the bulbocavernosus/levator ani with a local anesthetic increased the number of SNB motoneurons expressing alpha-CGRP mRNA and CGRP immunoreactive neurons. To determine whether nerve damage accounted for the observed effects following injection of anesthetic, the pudendal nerves were cut bilaterally.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of pulse oximetry and respiratory rate in patient screening

Objective: To examine how well respiratory rate correlates with arterial oxygen saturation status as measured by pulse oximetry, and determine whether respiratory rate measurements detect oxygen desaturation reliably.Methods: Respiratory rate (RR) and oxygen saturation (SaO₂) were measured prospectively on 12 096 consecutive adult emergency department triage patients at a university medical center. Respiratory rate was measured by counting ausculated breath sounds for 1 min. Pulse oximetry was used to measure SaO₂. Measurements were analysed by age (with one group for 18–19 year olds, groups for every 10 yr from age 20 to age 60, and groups for every 5 yr for subsequent ages). Pearson correlation coefficients were calculated for each age group as well as the weighted average coefficient. Cases having oxygen saturation below 90% were examined to determine how frequently they exhibited increased RR (increased RRs were defined as any rate in the upper five percentile by age.Results: Correlation coefficients ranged from 0·379 to −0·465 with a weighted mean of −0·160. Coefficients for ages 18 through 70 years (representing 10 740 patients) all had magnitude <0·252. Overall, only 33% of subjects with oxygen saturation below 90% exhibited increased RR.Conclusions: Respiratory rate measurements correlate poorly with oxygen saturation measurements and do not screen reliably for desaturation. Patients with low SaO₂ do not usually exhibit increased RR. Similarly, increased RR is unlikely to reflect desaturation.     

The effect of hypoprolactinemia alone and in combination with cyclosporine on allograft rejection

Recent evidence suggests that prolactin has a role in regulating immune function. Hypophysectomy or administration of bromocriptine results in suppression of the immune response, which is reversed by the administration of prolactin. Hypoprolactinemia has been shown to augment the immunosuppressive effect of cyclosporine. We studied the effect of hypoprolactinemia induced by a new drug, CQP 201-403, on the survival of heterotopic cardiac allografts in the rat and the ability of peripheral blood lymphocytes to respond in vitro to plant mitogens. CQP treatment alone produced a small increase in graft survival but no change in lymphocyte in vitro proliferation (P less than 0.05). CQP treatment greatly enhanced the immunosuppressive effect of cyclosporine on graft rejection and in vitro lymphocyte function (P less than 0.02). We conclude that modulation of prolactin may be a useful adjunct to cyclosporine immunosuppression.     

A randomized, blinded trial of uncooked cornstarch to diminish nocturnal hypoglycemia at Diabetes Camp

Objective: To determine if uncooked cornstarch, as part of the evening snack, can avert nocturnal hypoglycemia in type 1 diabetes. Research Design and Methods: Fifty-one campers and counselors at the American Diabetes Association Camp in San Bernardino, CA were randomly assigned to receive 5 g of uncooked cornstarch as part of the 21:00 evening snack vs. a standard snack of equivalent carbohydrate content. Each snack was given for five nights and the participants and medical personnel were blinded as to assignment. Midnight and 07:00 finger stick blood glucose levels were compared with values <60 mg/dl defined as hypoglycemia and values >250 mg/dl defined as hyperglycemia. Results: There were 218 midnight and 222 07:00 values for comparison. There were six episodes of hypoglycemia at midnight and nine episodes of hypoglycemia at 07:00 for the cornstarch snack nights vs. 30 hypoglycemia episodes at midnight and 21 at 07:00 for the standard snack nights (P < 0.001 and < 0.05, respectively). There was no difference in the number of hyperglycemic events at midnight or 07:00 for the cornstarch vs. standard snack nights. At midnight, 12% of campers had hypoglycemia after the cornstarch snack vs. 46% after the standard snack (P < 0.001), and at 07:00, 16% had hypoglycemia after cornstarch vs. 26% after the standard snack (P = 0.327). Conclusions: These data suggest that uncooked cornstarch, as part of the evening snack, can diminish the nighttime and morning hypoglycemia associated with type 1 diabetes, without causing hyperglycemia.     

Comparison of the blood-brain barrier and liver penetration of acridine antitumor drugs

Summary The blood-brain barrier penetration of amsacrine and its analogs 9-({2-methoxy-4-[(methylsulfonyl)-amino]phenyl}amino)-,5-dimethyl-4-acridine carboxamide (CI-921) and M-[2-(dimethylamino)ethyl]-acridine-4-carboxamide (AC) was measured in the barbiturate-anesthetized mouse. After intracarotid administration, AC was almost completery extracted (90%) in a single transit through the brain capillaries, whereas CI-921 (20%) and amsacrine (15%) were moderately extracted. AC is retained in the brain; no loss of AC from the brain was apparent at 1, 2, 4, or 8 min after injection. In contrast, after intraportal administration, 75% of the AC, 94% of the CI-921, and 57% of the amsacrine was extracted in a single transit through the hepatic vasculature. Rather than being retained in the mouse liver, these acridine antitumor agents show time-dependent loss (t _1/2=10 min for amsacrine and AC, 24 min for CI-921). We conclude that unlike most antitumor agents, these acridine drugs appear to penetrate the blood-brain barrier readily.This study was supported by the Auckland Medical Research Foundation (New Zealand), by the Medical Research Foundation (New Zealand), by the National Science Foundation (United States/New Zealand Cooperative Science Program), by the United States Veterans Administration, and by NIH grant NS 25554     

Sebaceous carcinoma of the head and neck. Case report and literature review.

Sebaceous carcinoma is uncommon, with fewer than 400 cases reported. Usually, lesions arise in the meibomian glands of the eyelid; however, extraocular lesions within the head and neck have been reported. Regardless of the location, sebaceous malignancies must be considered aggressive neoplasms with a potential for regional and distant metastasis. Diagnosis may be difficult, given the low incidence and inconsistencies in histopathologic classification. Recently, needle aspiration cytologic characteristics have been delineated, with this procedure becoming increasingly useful in establishing the diagnosis. Treatment requires wide surgical excision with removal of involved regional lymph nodes. Opinions are divided regarding the use of postoperative irradiation or chemotherapy. Records of all patients with sebaceous carcinoma of the head and neck treated at UCLA Medical Center, Los Angeles, over the last 35 years were reviewed. The clinical and pathologic features are discussed, and the literature is summarized.     

Heme-dependent activation of guanylate cyclase by nitric oxide: a novel signal transduction mechanism.

The interaction between nitric oxide (NO) synthesized in one cell and cytosolic guanylate-cyclase-bound heme located in adjacent target cells to generate the NO-heme adduct of guanylate cyclase represents a novel and widespread signal transduction mechanism that links extracellular stimuli to the biosynthesis of cyclic GMP in target cells. A variety of chemical factors interact with selective extracellular receptors and trigger the biosynthesis of NO from L-arginine. The unique chemistry of NO endows this molecule with the capacity to diffuse rapidly into nearby cells and stimulate cyclic GMP formation. Cyclic GMP acts as a messenger in each cell type to trigger different but complementary cellular responses within a localized environment. This transcellular signaling is a form of rapid intercellular communication allowing the simultaneous local initiation of increased blood flow, inhibition of platelet-induced thrombosis and other cellular functions.