Daily variability in resting levels of cardiovascular variables in normal subjects and those with homozygous sickle cell disease

Measurements were made of cardiovascular variables and oral temperature in 16 male subjects with homozygous sickle cell disease (SS) and in 17 matched controls (AA) at 10.00 a.m., 1.00 p.m. and 4.00 p.m. All subjects were in a rested state throughout. At 10.00 a.m., mean arterial pressure was lower, while heart rate, total forearm blood flow and cutaneous red cell flux in the forearm were higher in SS than AA. Vascular resistance in total forearm and forearm skin, calculated by dividing arterial pressure by blood flow or red cell flux, were lower in SS but hand cutaneous red cell flux and vascular resistance were not significantly different in SS and AA. In both SS and AA, there were parallel increases over the three sessions, in mean arterial pressure (by 12 and 10%, respectively) forearm vascular resistance (by 17 and 27%) and hand cutaneous vascular resistance and hand cutaneous resistance (by 240 and 350%) whereas forearm blood flow and hand cutaneous red cell flux fell. By contrast, forearm cutaneous resistance showed no change during the day in SS, but increased progressively in AA (by 75%). These results indicate that, during the day, there is progressive vasoconstriction in forearm muscle and hand skin in SS and AA and also in forearm skin of AA that contributes to a progressive rise in the resting level of mean arterial pressure. We suggest this daily variability should be considered in studies of cardiovascular function: within a given study they should be performed at the same time of day.     

Epidemiology of childhood hepatitis B in India: Vaccination related issues

It has been estimated that presently hepatitis B kills more people every day than AIDS kills in a year world-wide. Infection with hepatitis B produces a wide range of manifestations ranging from asymptomatic carriers to persistent infections leading to chronic liver diseases and hepatocellular carcinoma. Availability of effective and safe vaccine has made all this preventable. To formulate on appropriate vaccination strategy for India the epidemiology of hepatitis B needs to be defined. This report critically reviews the available data. The burden of long term sequelae of HBV infection is probably under-diagnosed and under-reported in India. Prevalence studies of HBV markers indicate that India falls under the area of intermediate endemicity. Limited data on agespecific prevalence of HBV markers suggests that the majority of the infection seems to take place below 15 years of age, and most of it under one year. Perinatal transmission appears to contribute significantly to the carrier pool. Childhood vaccination for HB among the general population is the obvious strategy of choice. But more information is required to decide on the timing of the first dose.     

Effect of whole-body vibration on the low back. A study of tractor-driving farmers in north India

STUDY DESIGN: A retrospective cohort study of tractor-driving farmers (study group) and non-tractor-driving farmers (control group) matched for age, gender, generic/ethnic group, land-holding, and work routines. OBJECTIVES: To determine, using magnetic resonance imaging and clinical investigations, the effect of whole-body vibrations on the back in tractor-driving farmers. SUMMARY OF BACKGROUND DATA: Low back pain and pathologic changes in the lower backs of tractor drivers have been reported. However, no study with a control group matched for work-related risk factors has been reported. METHODS: Fifty tractor-driving farmers were compared with 50 non-tractor-driving farmers matched for age, gender, ethnic group, land-holding, and work routine. Both groups were interviewed for details of work routine, assets held, family profile, and vibration exposure to assess the influence of these parameters on signs and symptoms of backache. Magnetic resonance imaging was done to assess the effect of exposure on whole-body vibration and degenerative changes in the back. Vibration measurements also were done on tractors to observe the actual severity of the vibrations. RESULTS: Regular work-related backache was more common among tractor-driving farmers (40%) than among non-tractor-driving farmers (18%, P = 0.015). Anthropometric evaluation showed abdominal girth and weight to be significantly higher in tractor-driving farmers (P = 0.006 and 0.046, respectively), whereas while height and arm span were similar between the two groups. Clinical examination for evidence of disc or facet degeneration showed no difference between the two groups. Evaluation of magnetic resonance images of tractor-driving farmers and non-tractor-driving farmers by an orthopedic surgeon, radiologist, and neurosurgeon showed degenerative changes to be similar between the two groups (P > 0.050). CONCLUSIONS: Tractor-driving farmers report backache more often than non-tractor-driving farmers, but no significant objective differences on clinical or magnetic resonance imaging evaluation were found between the two groups.     

Mycotic keratitis in non-steroid exposed vernal keratoconjunctivitis.

PURPOSE: To report a patient with vernal keratoconjunctivitis who developed mycotic keratitis in absence of known risk factors. METHODS: A 17-year-old male suffering from vernal keratoconjunctivitis presented with infective keratitis. The patient had been treated in the past with topical antihistaminics and vasoconstrictors. The patient had not been exposed to topical steroids in 2 years of follow-up. He did not have dry eye or corneal micro or macroerosions prior to the development of infective keratitis. Corneal scrapings were obtained and subjected to KOH wet mount smear, calcofluor and Grams stain as well as bacterial culture sensitivity and fungal culture. RESULTS: Clinical diagnosis of mycotic keratitis in association with vernal conjunctivitis was supported by microbiological investigations. KOH wet mount and calcofluor staining showed presence of filamentous septate hyphae while fungal culture showed growth of aspergillus fumigatus. Antifungal therapy was initiated in the form of topical natamycin 5% suspension to which the patient responded and recovered 6/6 final visual acuity. CONCLUSION: The authors wish to conclude that patients suffering from vernal keratoconjunctivitis, even in the absence of corneal involvement, steroid exposure and trauma, may be at increased risk of developing keratomycosis.     

5-Hydroxytryptamine-induced increase in left ventricular dP/dtmax does not suggest the presence of ventricular 5-HT4 receptors in the pig

Summary Although 5-hydroxytryptamine (5-HT) increases porcine atrial force and rate via 5-HT₄ receptors, its effect on left ventricular contractility is not known. Therefore, using the maximum rate of rise of left ventricular pressure (LVdP/dt_max) as an index of cardiac contractility, we have attempted to analyze the possible role of ventricular 5-HT₄ receptors in the anaesthetized pig. The full agonists at 5-HT₄ receptors, 5-HT and 5-methoxytryptamine (each 3, 10 and 30 g · kg^–1), and the -adrenoceptor agonist, isoprenaline (0.01, 0.03 and 0.1 g · kg^–1), increased heart rate, LVdP/dt_max and cardiac output. For a given degree of tachycardia, the increase in LVdP/dt_max by isoprenaline was substantially more than that observed with either 5-HT or 5-methoxytryptamine. The 5-HT₄ receptor partial agonist, renzapride (3, 10, 30, 100 and 300 g · kg^–1), also increased heart rate and LVdP/dt_max dose-dependently. When the heart was paced at 150 beats · min^–1, increases in LVdP/dt_max as well as cardiac output (except with the highest doses) by 5-HT, 5-methoxytryptamine and isoprenaline were clearly attenuated. However, the magnitude of attenuation of LVdP/dt_max responses by cardiac pacing was more marked in the case of 5-HT and 5-methoxytryptamine than with isoprenaline.The effects of renzapride (300 g · kg^–1) and tropisetron (0.3 and 3 mg · kg^–1) on increases in heart rate and LVdP/dt_max by 5-HT, 5-methoxytryptamine and isoprenaline were also studied. In the absence of atrial pacing, both renzapride and tropisetron (3 mg · kg^–1) effectively antagonized the responses to 5-HT and 5-methoxytryptamine; except for some decrease in the LVdP/dt_max response by tropisetron, the effect of isoprenaline remained essentially unchanged after the antagonists. During atrial pacing, renzapride significantly antagonized the responses to the first two doses of 5-HT, but the responses to the highest 5-HT dose and to 5-methoxytryptamine remained unaffected. Though, particularly after its higher dose, tropisetron reduced the responses to 5-HT and 5-methoxytryptamine, isoprenaline responses were also affected.The above results show that a significant part of the increase in LVdP/dt_max by 5-HT receptor agonists in the anaesthetized pig is a consequence of tachycardia elicited by these compounds via 5-HT₄ receptors. Since the increase in LVdP/dt_max, compared to tachycardia, was much less with 5-HT and 5-methoxytryptamine than with isoprenaline, and since the antagonism by renzapride and tropisetron against 5-HT and 5-methoxytryptamine during atrial pacing was relatively weaker and/or unspecific, it appears unlikely that the increase in LVdP/dt_max, during atria] pacing is mediated by ventricular 5-HT₄ receptors. This view is substantiated by our recent in vitro experiments where 5-HT (0.01 to 100 mol/l) failed to significantly increase contractions of porcine left ventricular trabeculae.Correspondence to P. R. Saxena at the above address     

Effects of Nd-YAG laser on platelet function in vitro: A comparative study using the spectraprobe, ‘hot tip’ and bare fibres

The effects of Nd-YAG laser irradiation on platelet function in vitro were studied using platelet rich plasma obtained from the blood of healthy volunteers. Laser delivery was effected via the bare optical fibre, thermal hot tip fibre and spectraprobe and the effects of these probes on platelet function were compared. Fall in platelet count and mean platelet volume (MPV) were proportional to increasing energy delivery with all three probes, the effect being maximal with the spectraprobe, moderate with the hot tip and least with the bare optical fibre. A significant decrease in percentage aggregation of platelets in response to added ADP, collagen and ristocetin with increasing energy delivery was also observed with all three probes. The formation of preformed aggregates, however, showed an increase proportional to energy delivery with all three probes.The differential effects of the various probes used in this study on platelet function may enhance our understanding of the complex role played by platelets in the pathogenesis of complications such as arterial thrombosis and re-occlusion after laser angioplasty.     

Unusual presentation of a giant glomus tumor

Giant glomus tumors pose a challenge to the Otologist by virtue of their location and vascularity. A vast majority of them present with tinnitus, conductive hearing loss and cranial nerve palsies. We report the case of a 16-year-old male patient who presented with sudden right-sided sensorineural hearing loss. This is an unusual presentation of a giant glomus tumor. We present the clinical features and management of this unusual case.     

Development of standard therapeutic guidelines for selected common diseases for the primary health care centres of a South Indian district

Method A questionnaire survey of medical officers was conducted to collect data on the most commonly‐presenting diseases and doctors' treatment choices in PHCs in Mysore. Draft guidelines were developed for these conditions based on available literature, together with microbiological sensitivity data from the three district hospitals. User feedback on the draft guidelines and on guidelines in general was obtained from medical officers using a postal questionnaire. Objective To develop standard therapeutic guidelines for selected common diseases for the primary health care centres (PHCs) of a South Indian district and to evaluate medical officers' perceptions about the proposed guidelines and about guidelines in general. Setting Sample of 17 of the 93 PHCs in Mysore. Key findings Upper respiratory tract infection was the most commonly‐presenting condition. Procaine penicillin was the most commonly‐used drug and there were examples of inappropriate treatment choices. The survey produced evidence that access to medicines on the government's “essential” list was not uniform, with many patients having to purchase prescribed drugs that were not on the list. The response rate to the user feedback questionnaire was 62 per cent (31 doctors). The medical officers had positive opinions about guidelines in general and felt that the guidelines we proposed were useful and would help them to improve their prescribing habits. Conclusions Prescribing in primary care in India needs to be improved. The involvement of potential users of the guidelines in their development should increase their acceptability and thus their use in practice.     

Development and Application of a Serum C-Telopeptide and Osteocalcin Assay to Measure Bone Turnover in an Ovariectomized Rat Model

Biochemical markers applicable to the ovariectomized rat model can provide important tools for studying the bone remodeling process in this animal model of postmenopausal osteoporosis. We describe the development and application of two biochemical markers, a C-telopeptide (of type-I collagen) enzyme-linked immunosorbent assay (ELISA) for measuring bone resorption and an osteocalcin radioimmunoassay (RIA) for measuring bone formation in rat serum. The C-telopeptide ELISA is based on an affinity purified polyclonal antibody generated against human sequence DFSFLPQPPQEKAHDGGR. The antibody epitope involves amino acid sequence, which is similar in rat and human carboxyl terminal peptide of type-I (alpha 1) collagen. Sensitivity of the ELISA was 0.3 ng/ml. The averaged intra- and interassay variation was CV <7%. Averaged dilution and spiked recoveries were 91% and 105%, respectively. The second marker developed is a synthetic peptide-based osteocalcin RIA, which does not require isolation and purification of intact osteocalcin from rat bone. Osteocalcin antiserum used in the RIA was generated in rabbits against a synthetic peptide comprising amino acids 33–49 of the rat osteocalcin sequence. The sensitivity of the RIA was 0.15 ng/ml of peptide. The averaged intra (n = 10) and interassay variations for two controls were CV <9% and 12%, respectively. The averaged dilution and spiked recoveries were 99.6%. In vivo validation of the C-telopeptide ELISA and osteocalcin RIA was performed in an ovariectomized (OVX) rat model. In 12-week-old OVX Sprague Dawley rats, the C-telopeptide and osteocalcin concentrations were approximately 65% and 40%, respectively, higher than the sham group. Estradiol repletion significantly lowered the C-telopeptide and osteocalcin concentration to the levels of the sham group. In addition, changes in serum C-telopeptide concentration correlated negatively with trabecular BMD measured by pQCT (r =−0.51, P < 0.001). In conclusion, the C-telopeptide ELISA and osteocalcin RIA exhibited required sensitivity, accuracy, and adequate discriminatory power to be used for measuring bone resorption and bone formation in the ovariectomized rat model. Received: 20 August 1999 / Accepted: 5 January 2000