Radiofrequency ablation in the management of primary hepatic and biliary tumors

In the United States, 80%-90% of primary hepatic tumors are hepatocellular carcinomas and 10%-15% are cholangiocarcinomas (CCA), both with high mortality rate, particularly CCA, which portends a worse prognosis. Traditional management with surgery has good outcomes in appropriately selected patients; however, novel ablative treatment options have emerged, such as radiofrequency ablation (RFA), which can improve the prognosis of both hepatic and biliary tumors. RFA is aimed to generate an area of necrosis within the targeted tissue by applying thermal therapy via an electrode, with a goal to completely eradicate the tumor while preserving surrounding healthy tissue. Role of RFA in management of hepatic and biliary tumors forms the focus of our current mini-review article.

Utility of endoscopic ultrasound and endoscopy in diagnosis and management of hepatocellular carcinoma and its complications: What does endoscopic ultrasonography offer above and beyond conventional cross-sectional imaging?

Hepatocellular carcinoma constitutes over 90% of the primary liver tumors, the rest being cholangiocarcinoma. It has an insidious presentation, which is responsible for the delayed presentation. Hence, the management strategy relies on screening to diagnose it an early stage for curative resection and/or treatment with local ablative techniques or chemotherapy. However, even with different screening programs, more than 60% of tumors are still detected at an advanced stage, leading to an unchanged mortality rate, thereby implying a room for improvement in the screening and diagnostic process. In the last few years, there has been evolution of utility of endoscopy, specifically endoscopic ultrasonography along with Fine needle aspiration, for this purpose, which we comprehensively review in this article.

Spontaneous pituitary apoplexy during the second trimester of pregnancy, with sensory loss

A 32-year-old Hispanic woman at 23 weeks gestation presented with right-sided headache, associated with photophobia and right-sided numbness. She denied visual problems, menstrual irregularities and galactorrhoea. Examination revealed visual acuity 20/40 bilaterally with some blurriness on the left side, decreased right V1-V2 facial sensation and preserved 5/5 power, but decreased sensation over the entire right upper extremity (RUE) and right lower extremity (RLE) to touch and pinprick. Laboratories suggested normal pituitary function, but MRI of the brain revealed enlargement of the pituitary (1.7 cm), with layering haemorrhage posteriorly and mild compression of the optic nerve. The patient underwent emergent evacuation of a pituitary haematoma, and histology revealed minute fragments of adenohypophysis with haemorrhage and fibrosis.

Short-term outcomes of a program developed to inculcate research essentials in undergraduate medical students

BACKGROUND

Participation in research during undergraduate studies may increase students' interest in research and inculcate research essentials in them.

AIMS

The purpose of this study was to evaluate the effectiveness of the mentored student project (MSP) program.

SETTINGS AND DESIGN

In the MSP program, students in groups (n = 3 to 5) undertook a research project, wrote a scholarly report, and presented the work as a poster presentation with the help of a faculty mentor. To begin with, the logic model of the program was developed to identify short-term outcomes of the program on students, mentors, and the institution. A quasi-experimental design was used to measure the outcomes.

MATERIALS AND METHODS

A mixed method evaluation was done using a newly-developed questionnaire to assess the impact of the MSP on students' attitude, a multiple-choice question (MCQs) test to find out the impact on students' knowledge and grading of students' project reports and posters along with a survey to check the impact on skills. Students' satisfaction regarding the program and mentors' perceptions were collected using questionnaires. Evidence for validity was collected for all the instruments used for the evaluation.

STATISTICAL ANALYSIS

Non-parametric tests were used to analyze data. Based on the scores, project reports and posters were graded into A (>70% marks), B (60-69% marks), and C (<59% marks) categories. The number of MSPs that resulted in publications, conference presentation and departmental collaborations were taken as impact on the institution.

RESULTS

Students' response rate was 91.5%. The students' attitudes regarding research changed positively (P = 0.036) and score in the MCQ test improved (P < 0.001) after undertaking MSP. Majority of project reports and posters were of grade A category. The majority of the items related to skills gained and satisfaction had a median score of 4. The MSPs resulted in inter-departmental and inter-institutional collaborations, 14 publications and 15 conference presentations. An area for improvement noted was to have the MSP implemented in the curriculum without increasing students' overall workload and stress.

CONCLUSION

The study identified strengths and weaknesses of the MSP program. Our model of undergraduate research project may be incorporated in undergraduate medical programs to foster positive attitude and knowledge base about scientific research and to instil research skills among students.

Is short-term percutaneous endoscopic gastrostomy tube placement beneficial in acutely ill cognitively intact elderly patients? A proposed decision-making algorithm

AIM

Percutaneous endoscopic gastrostomy (PEG) tube is an important method of enteral feeding for patients who require temporary or long-term artificial nutritional support to prevent or correct disease-related malnutrition. However, there is paucity of data on the utility of short-term PEG tube placements in acute illnesses in cognitively intact older adults.

METHODS

We present a series of seven, cognitively intact patients (age range 72-93 years), who had PEG tubes placed for short periods. These patients were diagnosed with "failure to thrive" and were managed by placing a PEG tube temporarily for nutritional management. None of these patients had terminal illness or hospice eligibility, and all of the patients were community dwellers.

RESULTS

All of the elderly patients experienced good outcomes in terms of their functional status and nutritional support.

CONCLUSIONS

Our series clearly supports the notion that short-term PEG tube placement in cognitively intact elderly patients could be a successful strategy to support them during an episode of acute illness, and to improve their nutritional deficits and survival.

Management of gastric variceal bleeding: Role of endoscopy and endoscopic ultrasound

Gastric varices (GVs) are notorious to bleed massively and often difficult to manage with conventional techniques. This mini-review addresses endoscopic management principles for gastric variceal bleeding, including limitations of ligation and sclerotherapy and merits of endoscopic variceal obliteration. The article also discusses how emerging use of endoscopic ultrasound provides optimism of better diagnosis, improved classification, innovative management strategies and confirmatory tool for eradication of GVs.

Avenues for professional development: faculty perspectives from an Indian medical school

BACKGROUND

Medical school faculty in India are challenged to balance teaching and professional development. Melaka Manipal Medical College (MMMC), Manipal Campus, Manipal University, India offers the Bachelor of Medicine and Bachelor of Surgery (MBBS) program. The institution incorporates certain effective practices based on adult learning principles which are aimed at fostering the professional development of faculty members.

OBJECTIVES

The present study was undertaken to explore the perceptions of faculty members regarding the scope for professional development at Melaka Manipal Medical College, Manipal Campus.

METHODS

In September 2009, a questionnaire comprising items (23) focusing on five adult learning principles (active participation, relevant learning, constructive feedback, safe, non-threatening environment and previous experiences) was designed and faculty members (n=23) were asked to respond to it on a 5-point Likert scale. Additionally, a force field analysis was conducted by asking the faculty to identify three factors which facilitated them to consciously get involved in professional development activities. They were also asked to identify three unfavorable factors that hindered their professional development.

RESULTS

Among the five characteristics, relevant learning was found to have a high mean score. Frequency analysis of responses revealed that at Melaka Manipal Medical College, there was ample scope for relevant self-learning that fosters professional development (91.3%). Force field response analysis revealed Melaka Manipal Medical College offered considerable flexibility and opportunities for continuing professional development along with faculty members' prevailing role as teachers. Nevertheless, the need for more research facilities and funds was highlighted.

CONCLUSIONS

Adherence to adult learning principles may provide avenues for professional development in medical schools. An organized attempt to make the medical school faculty aware of the scope of these practices appears to be necessary to nurture professional development in settings where there are resource constraints.

Fostering research skills in undergraduate medical students through Mentored Student Projects: Example from an Indian medical school

Background Healthcare decision-making is largely reliant on evidence–based medicine; building skills in scientific reasoning and thinking among medical students becomes an important part of medical education. Medical students in India have no formal path to becoming physicians, scientists or academicians. Objectives This study examines students’ perceptions regarding research skills improvement after participating in the Mentored Student Project programme at Melaka Manipal Medical College, Manipal Campus, India. Additionally, this paper describes the initiatives taken for the continual improvement of the Mentored Student Project programme based on faculty and student perspectives. Methods At Melaka Manipal Medical College, Mentored Student Project was implemented in the curriculum during second year of Bachelor of Medicine and Bachelor of Surgery programme with the intention of developing research skills essential to the career development of medical students. The study design was cross-sectional. To inculcate the spirit of team work students were grouped (n=3 to 5) and each group was asked to select a research project. The students’ research projects were guided by their mentors.  A questionnaire (Likert’s five point scale) on students’ perceptions regarding improvement in research skills after undertaking projects and guidance received from the mentor was administered to medical students after they had completed their Mentored Student Project . The responses of students were summarised using percentages. The median grade with inter-quartile range was reported for each item in the questionnaire. The median grade for all the items related to perceptions regarding improvement in research skills was 4 which reflected that the majority of the students felt that Mentored Student Project had improved their research skills. The problems encountered by the students during Mentored Student Project were related to time management for the Mentored Student Project and mentors. Results This study shows that students acknowledged that their research skills were improved after participating in the Mentored Student Project programme. Conclusions The Mentored Student Project programme was successful in fostering positive attitudes among medical students towards scientific research. The present study also provides scope for further improvement of the Mentored Student Project programme based on students’ and faculty perspectives.DOI: http://dx.doi.org/10.3126/kumj.v8i3.6215 Kathmandu Univ Med J 2010;8(3):294-8

Clinical predictors of fulminant colitis in patients with Clostridium difficile infection

BACKGROUND/AIM

Clostridium difficile infection (CDI) can affect up to 8% of hospitalized patients. Twenty-five percent CDI patients may develop C. difficile associated diarrhea (CDAD) and 1-3% may progress to fulminant C. difficile colitis (FCDC). Once developed, FCDC has higher rates of complications and mortality.

PATIENTS AND METHODS

A 10-year retrospective review of FCDC patients who underwent colectomy was performed and compared with randomly selected age- and sex-matched non-fulminant CDAD patients at our institution. FCDC (n=18) and CDAD (n=49) groups were defined clinically, radiologically, and pathologically. Univariate analysis was performed using Chi-square and Student's t test followed by multivariate logistic regression to compute independent predictors.

RESULTS

FCDC patients were significantly older (77 ± 13 years), presented with triad of abdominal pain (89%), diarrhea (72%), and distention (39%); 28% had prior CDI and had greater hemodynamic instability. In contrast, CDAD patients were comparatively younger (65 ± 20 years), presented with only 1 or 2 of these 3 symptoms and only 5% had prior CDI. No significant difference was noted between the 2 groups in terms of comorbid conditions, use of antibiotics, or proton pump inhibitor. Leukocytosis was significantly higher in FCDC patients (18.6 ± 15.8/mm³ vs 10.7 ± 5.2/mm³; P=0.04) and further increased until the point of surgery. Use of antiperistaltic medications was higher in FCDC than CDAD group (56% vs 22%; P=0.01).

CONCLUSIONS

Our data suggest several clinical and laboratory features in CDI patients, which may be indicative of FCDC. These include old age (>70 years), prior CDI, clinical triad of increasing abdominal pain, distention and diarrhea, profound leukocytosis (>18,000/mm³), hemodynamic instability, and use of antiperistaltic medications.

Novel medical therapies of recurrent and metastatic gastroenteropancreatic neuroendocrine tumors

Neuroendocrine tumors (NETs) of the gastrointestinal tract and pancreas are slow-growing but commonly advanced malignancies with increasing incidence and prevalence. While locoregional disease can be effectively managed with resection, treatment of recurrent, progressive or metastatic disease has until recently been limited to palliative embolization and cytoreducitve surgery, with cytotoxic chemotherapeutic agents being the last resort. However, novel molecular targeted therapies inhibiting malignant cell proliferation and neoangiogenesis, as well as new cytotoxic chemotherapy drugs and somatostatin analogues, are all being investigated for their potential use in advanced neuroendocrine tumors. Long-acting release forms of octreotide have been shown to not only improve symptoms in carcinoid syndrome but to also delay progression of gastrointestinal NETs. On the other hand, phase III trials have demonstrated everolimus (with octreotide) and sunitinib to increase progression-free survival in pancreatic NETs. Use of bevacizumab has also shown promise in a phase II study, and results of an ongoing phase III trial comparing it to interferon are eagerly expected. Use of radiolabeled somatostatin analogues is still under investigation, though several phase II studies are encouraging. New cytotoxic agents, most notably temozolomide and capecitabine, are already in use, but their relative effectiveness compared to streptozocin in pancreatic NETs is yet to be determined.

Learning approaches of undergraduate medical students to physiology in a non-PBL- and partially PBL-oriented curriculum

Melaka Manipal Medical College (Manipal Campus; Manipal, Karnataka, India) conducts the Bachelor of Medicine and Bachelor of Surgery program, for which the admission intakes are during the months of March and September. The present study was undertaken to study the differences in learning approaches to physiology of undergraduate medical students in a partially problem-based learning (PBL)- and non-PBL-oriented curriculum. PBL was introduced as a curricular reform for the September 2006 batch of students (partially PBL group), whereas it was not incorporated for the March 2006 batch of students (non-PBL group). Learning approaches to physiology of both groups of students were compared using the short inventory of approaches to learning. Mean scores for deep and strategic approaches were found to be significantly higher for the partially PBL group compared with the non-PBL group. The results of the present study support the earlier observation that PBL promotes a deep approach to learning.

The effects of vasoactive intestinal polypeptide and substance P on methacholine-induced sweating and vascular flare in diabetic neuropathy

Vasoactive intestinal polypeptide (VIP) and substance P (SP) immunoreactivity are reduced in the cutaneous nerves of diabetic patients with peripheral neuropathy. The functional significance of this finding was studied by measuring the forearm sweat response to intradermal methacholine and the effect of coadministration of VIP and SP in six normal subjects, and in six diabetic patients with neuropathy and eight without. Flare responses to the two peptides were also measured. Methacholine-induced sweat output was significantly greater in neuropathic patients compared with the other groups (p < 0.05), suggesting upper limb denervation supersensitivity. VIP and SP alone did not evoke sweating in any subject. Injection of VIP or SP reduced methacholine-induced sweating to a similar degree in all groups, except that the reduction was smaller in the non-neuropathic group than in the others (p = 0.028 versus normal subjects, p = 0.014 versus neuropathic diabetic patients). Flare responses to the peptides were markedly reduced in the neuropathic patients compared with the other groups (p < 0.01). In neuropathic patients, increased sweat responses and decreased flare coexist with diminished neurophysiological measurements; cutaneous sweating and flare responses provide valuable additional information to conventional methods of neurological assessment in diabetic neuropathy.

Portable infrared pupillometry using Pupilscan: relation to somatic and autonomic nerve function in diabetes mellitus

The relationship between dynamic pupillary function and peripheral nerve function was studied in 85 randomly-selected diabetic patients and 67 age-matched normals using a portable infrared pupillometer (Pupilscan Version 5). Seven measurements were chosen to represent different components of the pupillary constriction-redilatation curve after a standardized light stimulus. Constriction latency was significantly prolonged in diabetic patients (p = 0.05), as was time to 63% redilatation (p = 0.001). Thermal thresholds at the feet weakly correlated with relative reflex amplitude (warm: r = -0.22, p = 0.05; cool: r = -0.23, p = 0.05), but vibration perception thresholds were more strongly associated with constriction and redilatation velocity (r = -0.42, p = 0.001; r = -0.28, p = 0.03). Among the cardiovascular autonomic function tests, only respiratory R-R variation correlated with constriction velocity (r = 0.47, p < 0.001), and Valsalva ratio with redilatation velocity (r = 0.25, p = 0.04), but postural systolic blood pressure change was also correlated with reflex amplitude and latency time (r = -0.42, p < 0.001; r = 0.41, p = 0.001). There were no significant associations with three measures of sweating function in the feet. Pupil measurements were abnormal in 4-11% of diabetic patients, while other neurological tests were abnormal in 8-35%, consistent with the length-dependence of diabetic neuropathy. Median coefficients of variation were 2.0-7.2% in diabetic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative measures of sympathetic skin response in diabetes: relation to sudomotor and neurological function

The sympathetic skin response (SSR) at the foot to a deep inspiration was measured in 68 randomly selected diabetic patients and 46 age matched normal subjects and compared with other quantitative measures of neurological and sudomotor function. SSR was obtained in all but three diabetic patients. The upper limit of normal for the onset latency was 2202 ms and the lower limit for the amplitude of the first wave 92 microV. Ten diabetic patients had measurable but prolonged latencies, and 11 had measurable but low amplitudes. There were no significant associations between latency, height, and age, but in insulin dependent patients there was a significant diminution of response amplitude with increasing duration of diabetes. Latency was weakly associated with Marstock thermal thresholds, respiratory RR variation, and common peroneal nerve conduction velocity. SSR amplitude was associated with the density of pilocarpine activatable sweatspots in the same region of the foot. Patients with abnormal latencies were significantly older and had reduced thermal sensation than those with normal latencies. Median coefficients of variation for repeat testing in diabetic patients were 9% for latency and 13% for amplitude. The test is objective and reproducible, but latency measurements reflect conduction in a long multineuronal pathway and are not purely a measure of peripheral C fibre function; amplitude measurements reflect the density of spontaneously activable sweat glands and are therefore a valid measure of peripheral sympathetic activity, though they depend more on temperature than do latencies (mean change over the range 32-34 degrees C; 8.5% degrees C for amplitude, -2.5%/degrees C for latency).

Immunohistochemical measurements of nerves and neuropeptides in diabetic skin: relationship to tests of neurological function

Image-analysis was used to measure nerves immunoreactive to the general neuronal marker protein gene product 9.5 (PGP 9.5-IR) and the neuropeptides calcitonin gene-related peptide and vasoactive intestinal polypeptide in standardised leg skin biopsies of three age-matched groups of young subjects: non-diabetic (n = 14), diabetic patients with normal small fibre function ("non-neuropathic", (n = 11) and diabetic patients with abnormal small fibre function ("neuropathic", n = 11). Depletion of nerves and neuropeptides was most marked in the epidermis, where calcitonin gene-related peptide-immunoreactivity was more frequently absent than PGP 9.5-IR in diabetic patients. Epidermal PGP 9.5-IR nerve area and counts were reduced in neuropathic compared with normal subjects (p less than 0.001), as were epidermal calcitonin gene-related peptide nerve counts (p = 0.003). Sweat gland PGP 9.5 and vasoactive intestinal polypeptide, which may be involved in sweat production, showed no diminution in diabetic patients (area: p = 0.160, p = 0.372 by ANOVA). Two diabetic patients showed elevated sweat gland PGP 9.5-IR and three had increased sweat gland vasoactive intestinal polypeptide; this may represent nerve proliferation. In local sweat tests, acetylcholine-stimulated sweat output was associated with increased immunoreactivity, while the sympathetic skin response showed inverse correlations with immunoreactivity. There were no consistent changes with other commonly-used neurophysiological tests. HbA1 correlated negatively with immunohistochemical measurements. Neuropeptide changes were seen in the absence of macro- and microvascular disease, and epidermal nerve depletion occurred in patients with normal thermal thresholds and cardiac autonomic function.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in cholinergic sweat gland activation in diabetic neuropathy identified by computerised sweatspot analysis

Peripheral small-fibre denervation has been reported to result in decreased activation of eccrine sweat glands to muscarinic cholinergic agents. Using computerised image-analysis of pilocarpine-activated sweatspot prints of a 4 cm2 area of the dorsum of the foot in 79 randomly selected diabetic patients we have identified a group of neuropathic patients (18%) with decreased sweatspot activation (less than 20/cm2), and a smaller group (6%) of younger patients with less marked neuropathy who had increased activation (greater than 132/cm2), probably resulting from denervation supersensitivity. The associations between sweatspot density and other conventional tests of peripheral nerve function were weak. The prevalence of abnormal sweatspot density, 24%, was similar to that of other tests, except thermal thresholds at the feet (35-37%), which were not correlated with sweatspot activation, suggesting that diabetic neuropathy has differing effects on afferent and efferent small fibres. The method is rapid and reproducible (median coefficient of variation 14%) and its ability to identify patients with increased, as well as decreased, peripheral nerve function may be of value in the characterisation and longitudinal follow-up of small-fibre abnormalities in diabetes.

Assessment of basal and stimulated sweating in diabetes using a direct-reading computerized sudorometer

Abnormalities of eccrine sweating are thought to be common in diabetes. We describe a ventilated-capsule sudorometer for the continuous measurement of basal and stimulated sweat secretion. It is sensitive (detecting as little as 200 ng water vapour), precise, and stable. Since it measures dewpoint rather than relative humidity, it can be calibrated to read sweat volumes directly and independently of ambient temperature and humidity. Preliminary studies using this technique show that basal skin water loss is significantly diminished in patients with established diabetic neuropathy (0.91 +/- 0.18 g (+/- SD) cm-2 h-1) compared with normal subjects (1.21 +/- 0.39 g cm-2 h-1; p = 0.04) and non-neuropathic diabetic subjects (1.32 +/- 0.48 g cm-2 h-1; p = 0.04), and that local sweating induced by iontophoresis of 10 g l-1 acetylcholine is significantly reduced in diabetic subjects up to 5 min of recording (0.95 +/- 0.43 vs 1.26 +/- 0.40 mg; p = 0.02). In neuropathic subjects both low- and high-amplitude responses are seen, the latter probably representing denervation supersensitivity. Further studies with sensitive sudorometry should enable the mechanisms of these abnormal responses to be established.

The treatment of a hyperandrogenic and virilizing state in an elderly female with a synthetic LHRH agonist

A case of hyperandrogenism and virilization is described in an elderly female. She had elevated testosterone levels, but normal DHEAS and 24-h urinary 17-oxosteroid excretion, suggesting an ovarian tumor. Stimulation and suppression tests, and radioisotopic and radiological scans proved unhelpful in the diagnosis although hyperthecosis of the ovary was later suggested by ultrasound. Testosterone and gonadotropin levels fell during therapy with cyproterone acetate and subsequently ethinyl estradiol. Because of side effects encountered on these drugs, she was treated with a synthetic, slow-release preparation of an LHRH agonist, D-TRP-6-LHRH (Decapeptyl), with symptomatic and biochemical improvement. Long term LHRH agonists might be a valuable treatment for hyperandrogenic states in elderly patients.

Changes in thermal sensation in diabetic patients after treatment with gangliosides

Thirty diabetic patients (mean age (+/- SD) 45.7 +/- 11.4 years, mean duration of diabetes 7.5 +/- 7.0 years, 17 insulin-dependent), were given 3 months of placebo injections followed by either 3-4 or 6 months injections of 100 mg mixed gangliosides (Cronassial) every weekday intramuscularly in a double-blind placebo-controlled study. There was an improvement of 0.77 +/- 1.25(10) degrees C and 0.65 +/- 1.05(10) degrees C in the thermal thresholds of the Cronassial treated group after 13-19 weeks and greater than 20 weeks respectively (p less than 0.22 from change of 0.04 +/- 0.59 degrees C in group treated with placebo. Compared to those with normal thresholds, patients with abnormal thermal thresholds (greater than 1.2 degrees C) improved significantly after Cronassial treatment for 13-19 weeks (-1.13 +/- 1.72(12) vs. 0.03 +/- 0.45(16) degrees C, p less than 0.006) and for greater than 20 weeks (-1.83 +/- 1.46(6) vs. 0.06 +/- 0.59(11), p less than 0.004) but this may have been related to the fact that the degree of improvement in thermal sensation was correlated with the initial thermal threshold (r = -0.80(28), p less than 0.001). There were no significant changes in electrophysiological measurements or vibration thresholds. Gangliosides are known to increase nerve sprouting and dendritogenesis and their effects in diabetic patients may be more easily seen using tests of small fibre function.

Absence of the sensory action potential of the medial plantar nerve: a sensitive indicator of diabetic neuropathy

The sensory action potential of the medial plantar nerve (MPSAP), using needle recording electrodes subcutaneously, was measured in 119 patients with diabetes ((75 insulin-dependent, mean age 43.7 +/- 1.2 SEM years (range 15-73) and in 75 age-matched normal subjects (mean age 44.0 +/- 1.5 years (range 19-75)). The MPSAP was not detectable in 56 out of 119 diabetics; there was only one absent MPSAP response in the normal group, in a patient aged 71 years. Diabetics with absent MPSAP responses were significantly older, heavier and taller and had diabetes of longer duration. The amplitudes and conduction velocities in the sural, common peroneal, and tibial nerves were also significantly smaller. The amplitudes of the MPSAP, when present, correlated with height (r = -0.47(43), p less than 0.001), weight (r = -0.44(43), p less than 0.001), the distal tibial compound motor action potential (r = 0.37(43), p less than 0.01), and the common peroneal nerve conduction velocity (r = 0.32(43), p less than 0.02). The MPSAP was always absent if the sural SAP was less than 5uV but also in 14/59 patients whose sural SAP amplitudes were within 1 sd of the normal mean (greater than 10.7 uV). The MPSAP was absent at a younger age and with diabetes of shorter duration than is seen with unrecordable sural SAPs. It may therefore represent an early manifestation of neuropathy in diabetes.

Small- and large-fiber involvement in early diabetic neuropathy: a study with the medial plantar response and sensory thresholds

Small- and large-fiber function in diabetic neuropathy was studied in 68 patients (mean age 45.4 +/- 12.9 yr; 27 type I and 41 type II diabetics) with psychophysical tests of vibration and thermal sensation and neurophysiological measurements, including the medial plantar sensory action potential (MPSAP). Thermal sensitivity at the dorsolateral aspect of the foot (Pfizer thermal tester) correlated significantly with vibration thresholds (Somedic vibrameter) at three sites in the foot and two in the hand. Forty patients had normal sensory thresholds, but 18 of these lacked an MPSAP. Smaller groups had a single abnormal sensory threshold: 12 (18%) had an abnormal vibration threshold, and 24 (35%) had abnormal thermal sensitivity; 8 of the former group and 17 of the latter group lacked an MPSAP response. Only 8 (12%) had both abnormal vibration and thermal sensation (6 without an MPSAP). Fifteen of the 17 symptomatic patients had lost the MPSAP, but there was no consistent pattern of sensory loss. In this relatively young group of diabetics, more patients showed absent MPSAP responses than an abnormality in either sensory test on its own. The MPSAP is frequently absent in patients with no abnormalities in psychophysical tests of peripheral large-fiber function (vibration sensation) and small-fiber function (thermal sensitivity).

Evidence for the presence of the pituitary insulin secretagogue beta-cell trophin in human plasma

It has been demonstrated that the insulin secretagogue beta-cell-trophin, ACTH(22-39), is present in human plasma. The hormone, separated from plasma by affinity chromatography on a corticotrophin-like intermediate-lobe peptide antibody column, behaves similarly to synthetic beta-cell-trophin on a gel filtration column and on reverse-phase high-performance liquid chromatography. Sufficient amounts of the hormone were isolated from the plasma of two patients with Nelson's syndrome to demonstrate its biological activity on the perfused rat pancreas.

The effect of ovine corticotrophin releasing factor (oCRF), bromocriptine and TRH on the secretion of ACTH and alpha-MSH in Nelson's syndrome and Cushing's disease

The circulating levels of ACTH and alpha-melanocyte stimulating hormone (alpha-MSH) were measured in 9 patients with Nelson's syndrome after the administration of saline, ovine corticotrophin releasing factor (oCRF), bromocriptine or TRH. The concentrations of ACTH were grossly elevated and alpha-MSH levels ranged from undetectable to higher than the normal range. In seven of eight subjects there was a rapid corticotrophic response, but no change in the alpha-MSH level, following oCRF. This response was delayed in one subject. Following oCRF injection, the plasma oCRF profile was variable but circulating oCRF was detectable even at the end of the experiment in all cases. There was no significant change in circulating ACTH or alpha-MSH following either bromocriptine or TRH. Cultured tumour cells from one case of Cushing's disease showed a corticotrophic response but no change in alpha-MSH to oCRF and the response was enhanced by vasopressin. Bromocriptine added to the same tumour depressed ACTH secretion without affecting the output of alpha-MSH. The present data suggest that the tumours in these subjects are responsive to oCRF and arise from corticotrophs rather than melanotrophs.

Changes in bone and muscle constituents during dieting for obesity

The effects of dietary carbohydrate (CHO) content and of tri-iodothyronine (T3) administration on calcium, zinc and phosphate balances and on urinary hydroxyproline output were examined in eight obese subjects undergoing therapy with low energy (2741-3301 kJ/day), high calcium (28.9-35.1 mmol/day) diets. Calcium balances were generally positive at the high levels of intake used, but significantly more calcium was retained when dietary CHO intake (as proportion of total energy intake) was increased. Zinc balances were more positive when the proportion of dietary CHO was high and correlated both with nitrogen balance and with daytime insulin concentration. Urinary hydroxyproline output generally increased with dieting irrespective of dietary CHO content. Administration of T3 (30-80 micrograms/day) markedly increased zinc loss without affecting calcium balance.

Autonomic and electrophysiological studies in patients with signs or symptoms of diabetic neuropathy

Thirty-five patients with symptoms or signs of diabetic neuropathy were tested for autonomic neuropathy by measuring heart rate and blood pressure changes during an orthostatic tilt test, a single deep breath and the Valsalva manoeuvre and these results were related to electrophysiological measurements made on the common peroneal and sural nerves. The sural sensory action potential (SAP) was more strongly correlated with these tests of autonomic function (particularly with the brake index of the orthostatic tilt test (P less than 0.001) and the fall in systolic blood pressure 1 min after tilt (P less than 0.001], than the common peroneal nerve compound motor action potential, its minimum F wave latency or nerve conduction velocities. Patients with a detectable sural SAP had significantly higher brake indices than those with absent sural SAPs. Significant correlations were also obtained with the common peroneal motor nerve conduction velocity (MNCV) and autonomic tests and patients with MNCV less than and greater than 38 m/sec showed significant differences in many autonomic tests. The sural SAP amplitude, being less susceptible to factors that influence nerve conduction velocity, may be useful in identifying patients with an autonomic neuropathy.

The measurement and characterisation by high pressure liquid chromatography of immunoreactive alpha-melanocyte stimulating hormone in human plasma

Immunoreactive alpha-MSH was found in human plasma and in normal subjects ranged from less than 10-45 pg/ml. Plasma alpha-MSH concentrations were within the normal range in 13 out of 15 subjects during the last trimester of normal pregnancy and only just outside the normal range in the remaining two. Elevated plasma alpha-MSH concentrations were found in 6 of the 11 patients with Nelson's syndrome and in 10 of the 11 patients with pituitary dependent Cushing's disease. Separation on high pressure liquid chromatography (HPLC) revealed two major peaks of immunoreactivity. These peaks, which were identified as des-acetyl alpha-MSH and alpha-MSH were similar in size in normal subjects and Cushing's disease. In Nelson's syndrome, on the other hand, there was a greater proportion of des-acetyl alpha-MSH and it is possible that this peptide is secreted from tumour cells of anterior lobe origin. Although there was no correlation between the circulating alpha-MSH and the degree of pigmentation the high concentrations of plasma immunoreactive alpha-MSH in Cushing's disease and the HPLC profiles in Nelson's syndrome could provide useful information as to the localization of the defects in these particular disorders.

Congenital adrenal hyperplasia and XYY hypogonadism

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Corticotrophin, cortisol, prolactin and growth hormone responses to insulin-induced hypoglycaemia in normal subjects given sodium valproate

Plasma corticotrophin (ACTH), cortisol, prolactin and growth hormone (GH) responses to insulin-induced hypoglycaemia were measured in normal healthy subjects of both sexes before and after three weeks' treatment with sodium valproate (Epilim, 200 mg three times a day). The drug had no effect on fasting plasma glucose levels, or the extent of hypoglycaemia induced by insulin (0.15 U/kg). There was no significant difference between pre- and post-treatment values for basal or stress-induced concentrations of ACTH and cortisol (n = 12), prolactin (n = 7) or GH (n = 9). The results suggest that treatment of normal subjects with sodium valproate has no effect on the response of the hypothalamo-pituitary-adrenocortical axis to hypoglycaemia, which is in contrast to its inhibitory effects on ACTH secretion in patients suffering from Nelson's syndrome. This implies that in the disease state, there may be a unique sensitivity to GABA-ergic manipulation.

Method for estimating rate of fat loss during treatment of obesity by calorie restriction

Rates of weight and fat loss in sixteen female and nine male obese patients during calorie restriction (655-789 kcal/day) for up to 120 days were studied by a method for estimating daily changes in body composition. Fat mass is calculated by subtracting daily fluid (calculated from sodium and potassium balances) and protein mass changes from daily weight changes. After the natriuresis of the first 4 days, there was a slower rate of weight loss between days 5 and 28 due largely to a decreasing contribution from fluid and protein losses. No significant change in the rate of weight loss could be shown after the first 28 days. The rate of fat loss did not change significantly from day 5 onwards suggesting no significant change in total energy expenditure during the study period. After 68 days, 93.4% of the weight loss was fat.

The effects of triiodothyronine on energy expenditure, nitrogen balance and rates of weight and fat loss in obese patients during prolonged caloric restriction

We studied ten obese patients on prolonged caloric restriction by metabolic balance techniques two weeks before and two weeks after the start of treatment with triiodothyronine (T3) (0.36-1.01 micrograms/kg/d). The rate of weight, nitrogen and fat loss calculated from metabolic balance increased during T3 therapy and these effects were maximal in the second week of treatment. In seven patients studied continuously for four weeks on T3 therapy, the rates of weight and fat loss during the fourth week of treatment were not significantly different from pretreatment values while nitrogen loss was still significantly greater. The increase in nitrogen loss, studied after the period of adaptation to caloric restriction, implies that prolonged treatment with T3 can result in significant losses of lean tissue in addition to that resulting from caloric restriction alone. Mean weight loss increased by 92 g/d during T3 therapy. T3 significantly increased the metabolic rate as measured by two other independent measures: the resting energy expenditure (REE), measured by indirect calorimetry (fourteen patients), and the sleeping heart rate (six patients).

A double blind placebo controlled trial of mixed gangliosides in diabetic peripheral and autonomic neuropathy

Twenty-six patients with signs or symptoms of diabetic neuropathy who also had motor or sensory neurophysiological abnormalities, were intensively studied in the first double-blind, placebo controlled trial of a ganglioside mixture in the U.K. (Cronassial, Fidia Farmaceutici, Abano Terme, Italy; 6 weeks of 20 mg daily intramuscularly). Diabetes control was good in both groups and there was no deterioration in either group during the course of the trial. Of the five neurophysiological parameters measured - the motor nerve compound action potential, motor nerve conduction velocity and minimum f wave latency of the common peroneal nerve and the sensory action potential and conduction velocity of the sural nerve - only the mean motor nerve action potential and conduction velocity increased though the changes were not significant. Four patients showed improvements of greater than 1.0 mV after treatment with Cronassial while none of the placebo group did so (p less than 0.05). Of the four patients who showed dramatic improvements in motor nerve action potentials, three also showed improvements in motor nerve conduction velocity. There were no significant changes in three tests of autonomic function after Cronassial therapy (orthostatic tilt reactions, single deep breath and Valsalva maneuver). Four patients in the Cronassial group (not those showing neurophysiological improvement) but only one in the placebo group reported marked improvements in their symptomatic complaints after treatment. We conclude that Cronassial is a promising new drug for the treatment of diabetic peripheral neuropathy with clear benefits for some patients.

The evaluation of sodium valproate in the treatment of Nelson's syndrome

It has previously been reported that sodium valproate (Epilim) lowers plasma ACTH levels in Nelson's syndrome. This report describes further experience with its use. Ten patients with Nelson's syndrome were treated with sodium valproate (600-1200 mg/day) for 5-32 weeks. Plasma ACTH was measured by cytochemical methods and RIA. Initial treatment for 5-12 weeks significantly (P less than 0.005) lowered plasma ACTH from a pretreatment mean of 2460 +/- 1870 ng/liter to 480 +/- 330 ng/liter, and the ACTH circadian rhythm was restored in two patients. On discontinuing treatment, plasma ACTH levels remained suppressed for 3 weeks and rose to pretreatment values in 5-12 weeks. Two patients' plasma ACTH levels failed to show a second response to treatment, while a third patient had a favorable second response to treatment over 32 weeks. In six patients, skin pigmentation lightened with treatment, and in one patient, a reduction in size of a pituitary microadenoma, demonstrated radiographically, occurred with treatment. gamma-Aminobutyric acid and sodium valproate were shown to be ineffective in inhibiting ACTH secretion from cultured pituitary tumor cells from a patient with Nelson's syndrome. The results show that sodium valproate is effective in some cases of Nelson's syndrome. We suggest that it reduces the hypersecretion of ACTH by enhancing gamma-aminobutyric acid function in the hypothalamus, thereby inhibiting the release of corticotropin-releasing factor.

Controlled clinical trial of a new non-calorigenic sweetening agent

In a controlled trial of a double-blind cross-over design, it has been shown that "Marvie', a non-calorigenic sweetener containing 58 per cent maltitol by weight, is an effective sweetener which has no influence on routine haematological and biochemical parameters. The dose that could be tolerated without undesirable symptoms was between 20 and 30 g per day. Above this dose, flatus production with abdominal discomfort could limit tolerance to this sweetening agent.

Effect of treatment with sodium valproate and diazepam on plasma corticotropin in Nelson's syndrome

Six patients with Nelson's syndrome were given sodium valproate with or without diazepam for 3 or 5 weeks. Initial high plasma adrenocorticotropic hormone (ACTH) concentrations were greatly reduced by treatment and returned to high levels when treatment was stopped. Diazepam did not add significantly to the effects of sodium valproate alone. Three patients reported a decrease in the severity and frequency of headaches while on sodium valproate. In five patients abnormal skin pigmentation was reduced. Sodium valproate is a gamma-aminobutyric acid (GABA) transaminase inhibitor and it is suggested that the drug raises GABA levels in the hypothalamus and that this is responsible for the reduction in ACTH secretion. The data are consistent with the hypothesis that Nelson's syndrome is a neuroendocrine disease caused by a deficiency in the hypothalamic GABA-ergic system.

Hormonal control of intermediary metabolism in obese hyperglycemic mice. II. Levels of plasma free fatty acid and immunoreactive insulin and liver glycogen

In mice with genetic obesity, the plasma concentration of total free fatty acid (FFA) was not significantly raised, and no abnormality was detected in the response of the plasma level of FFA to noradrenaline. The plasma concentration of immunoreactive insulin (IRI) in the fed state was higher in obese than lean mice, even if glucose was given to lean mice. The content of liver glycogen was consistently higher in obese mice.

Following deprivation of food, plasma concentration of IRI decreased in obese mice, and that of FFA rose at the same rate as in lean mice. In obese mice which had been fasted for twenty-four hours or fed on a restricted quantity of food, the plasma level of IRI remained higher than in lean mice.

On oral administration of glucose to fasted mice, the decline in plasma FFA concentration, compared to that in animals which received saline, was similar in obese and lean mice. In response to glucose, the plasma IRI concentration increased rapidly in obese mice.

These results suggest that there is no primary impairment of adipose tissue triglyceride breakdown (“lipolysis”) in genetically obese mice, and that the hypersecretion of insulin in response to ingestion of food may more closely reflect their primary disorder.

Hormonal control of intermediary metabolism in obese hyperglycemic mice. I. The sensitivity and response to insulin in adipose tissue and muscle in vitro

The sensitivity and response to insulin in vitro of (a) the incorporation of U-C-14-glucose into glycogen in the isolated diaphragm muscle, and (b) the oxidation of l-C-14 glucose in the epididymal fat pad and in adipocytes, has been studied in obese hyperglycemic mice fed ad libitum, in obese mice fasted for twenty-four hours and in obese mice maintained on a restricted diet from weaning and in lean mice, at two to four months of age and at six to eight months of age.

In both age groups, there was a significant, although reduced, insulin effect in the muscle from obese mice but this was normal in the six to eight-month-old group of obese mice on a restricted diet.

The glucose oxidation in the epididymal fat pad of the obese mice fed ad libitum was very reduced in both age groups. Fasting the obese mice for twenty-four hours did not restore glucose oxidation to normal, but it was normal in fat pads from obese mice kept on a restricted diet. There was no insulin effect on the fat pad of obese mice in either age group even after a twenty-four-hour fast. The response and sensitivity of the tissue to insulin was partially restored in the obese mice on a restricted diet.

There were only small differences in sensitivity between adipocytes prepared from obese and lean epididymal fat pads. The maximum response to insulin in adipocytes from obese mice was usually lower than that in adipocytes from lean mice at glucose concentrations of 0.03 per cent but equal or higher at glucose concentrations of 0.2 per cent.

The clear responses to low concentrations of insulin of the isolated diaphragm muscle and adipocyte suspension from obese mice on a restricted diet and of the adipocytes from obese mice fed ad libitum, suggest that a decreased sensitivity to insulin at the cellular level is not the primary defect in the obese hyperglycemic syndrome.